Jesus must be tired after spending the whole night in prayer and then choosing 12 disciples to be apostles. It is now day, but he still has the strength and desire to help people. He does so on a mountainside in Galilee, perhaps not far from his center of activity in Capernaum.

Crowds have come to him from distant locations. Some are from down south, from Jerusalem and places in Judea. Others are from the coastal cities of Tyre and Sidon to the northwest. Why have they come looking for Jesus? “To hear him and to be healed of their sicknesses.” And that is just what happens​—Jesus is “healing them all.” Think of that! All the sick ones are healed. Jesus also ministers to “those troubled with unclean spirits,” people who are afflicted by the wicked angels of Satan.​—Luke 6:17-19.

Jesus next finds a level place on the mountainside and the crowd gathers around. His disciples, especially the 12 apostles, are probably nearest to him. All are eager to hear from this teacher who is able to perform such powerful works. Jesus delivers a sermon that clearly benefits his listeners. Since then, countless others have also benefited from it. We can too because of its depth of spiritual content presented with simplicity and clarity. Jesus draws on ordinary experiences and things familiar to people. This makes his ideas understandable to all who are seeking a better life in God’s way. What key aspects of Jesus’ sermon make it so valuable?

Everyone wants to be happy. Knowing this, Jesus begins by describing those who are truly happy. Imagine how this captures the attention of his listeners. But some things must puzzle them.

He says: “Happy are those conscious of their spiritual need, since the Kingdom of the heavens belongs to them. Happy are those who mourn, since they will be comforted. . . . Happy are those hungering and thirsting for righteousness, since they will be filled. . . . Happy are those who have been persecuted for righteousness’ sake, since the Kingdom of the heavens belongs to them. Happy are you when people reproach you and persecute you . . . for my sake. Rejoice and be overjoyed.”​—Matthew 5:3-12.

What does Jesus mean by saying “happy”? He is not referring to being jovial or mirthful, as when one is having a good time. Genuine happiness is deeper. It involves real contentment, a sense of satisfaction and fulfillment in life.

Jesus says that people who recognize their spiritual need, who are saddened by their sinful condition, and who come to know and serve God are the truly happy ones. Even if they are hated or persecuted for doing God’s will, they are happy because they know that they are pleasing him and that he will reward them with everlasting life.

Many people, though, think that being prosperous and pursuing pleasures are what makes one happy. Jesus says otherwise. Drawing a  contrast that must make many of his listeners think, he says: “Woe to you who are rich, for you are having your consolation in full. Woe to you who are filled up now, for you will go hungry. Woe, you who are laughing now, for you will mourn and weep. Woe whenever all men speak well of you, for this is what their forefathers did to the false prophets.”​—Luke 6:24-26.

Why do having riches, laughing in delight, and enjoying praise from others bring woe? Because when someone has and cherishes these things, serving God may be neglected at the cost of true happiness. Jesus is not saying that simply being poor or hungry makes one happy. However, it is often the disadvantaged person who responds to Jesus’ teachings and who gains the blessing of true happiness.

With his disciples in mind, Jesus says: “You are the salt of the earth.” (Matthew 5:13) Of course, they are not literal salt. Rather, salt is a preservative. A large amount of it is kept near the altar at God’s temple and is used to salt offerings. It also represents freedom from corruption or decay. (Leviticus 2:13; Ezekiel 43:23, 24) Jesus’ disciples are “the salt of the earth” in that their influence on people has a preserving effect, helping them to avoid spiritual and moral decay. Yes, their message can preserve the lives of all who respond to it.

Jesus also tells the disciples: “You are the light of the world.” A lamp is not put under a basket but is set on a lampstand, where it can shed light. So Jesus urges: “Let your light shine before men, so that they may see your fine works and give glory to your Father who is in the heavens.”​—Matthew 5:14-16.

The Jewish religious leaders view Jesus as a transgressor of God’s Law and recently conspired to kill him. So Jesus says openly: “Do not think I came to destroy the Law or the Prophets. I came, not to destroy, but to fulfill.”​—Matthew 5:17.

Yes, Jesus has the highest regard for God’s Law and urges others to have the same. In  fact, he says: “Whoever, therefore, breaks one of these least commandments and teaches others to do so will be called least in relation to the Kingdom of the heavens.” He means that such a person will not get into the Kingdom at all. “But,” he continues, “whoever does them and teaches them will be called great in relation to the Kingdom of the heavens.”​—Matthew 5:19.

Jesus condemns even attitudes that contribute to a person’s breaking God’s Law. After noting that the Law says “You must not murder,” Jesus adds: “Everyone who continues wrathful with his brother will be accountable to the court of justice.” (Matthew 5:21, 22) To continue wrathful with an associate is serious, perhaps even leading to murder. Hence, Jesus explains the extent to which one should go to achieve peace: “If, then, you are bringing your gift to the altar and there you remember that your brother has something against you, leave your gift there in front of the altar, and go away. First make your peace with your brother, and then come back and offer your gift.”​—Matthew 5:23, 24.

Another commandment of the Law is against adultery. Jesus comments: “You heard that it was said: ‘You must not commit adultery.’ But I say to you that everyone who keeps on looking at a woman so as to have a passion for her has already committed adultery with her in his heart.” (Matthew 5:27, 28) Jesus is not speaking merely about a passing immoral thought; rather, he is stressing the seriousness of the matter when one “keeps on looking.” Continued looking often arouses passionate desire. Then, if an opportunity arises, it can result in adultery. How can a person prevent this from happening? Extreme measures may be necessary. Jesus says: “If, now, your right eye is making you stumble, tear it out and throw it away from you. . . . If your right hand is making you stumble, cut it off and throw it away from you.”​—Matthew 5:29, 30.

To save their life, some people have willingly sacrificed a severely diseased limb. Understandably, Jesus says that it is more important to ‘throw away’ anything, even something as precious as an eye or a hand, to avoid immoral thinking and its resulting actions. “Better for you to lose one of your members,” Jesus explains, “than for your whole body to land in Gehenna” (a burning rubbish heap outside Jerusalem’s walls), which implies permanent destruction.

Jesus also offers counsel on dealing with people who cause injury and offense. “Do not resist the one who is wicked,” he says, “but whoever slaps you on your right cheek, turn the other also to him.” (Matthew 5:39) That is not to say that a person cannot defend himself or his  family if attacked. Jesus mentions a slap, which is not given to hurt severely or to kill another; rather, it is an insult. He is saying that if someone tries to provoke a fight or an argument, either by giving an openhanded slap or by using insulting words, do not retaliate.

That advice is in line with God’s law to love one’s neighbor. So Jesus advises his listeners: “Continue to love your enemies and to pray for those who persecute you.” He gives a powerful reason why: “So that you may prove yourselves sons of your Father who is in the heavens, since he makes his sun rise on both the wicked and the good.”​—Matthew 5:44, 45.

Jesus sums up this portion of his sermon, saying: “You must accordingly be perfect, as your heavenly Father is perfect.” (Matthew 5:48) Obviously, he does not mean that people can be fully perfect. However, by imitating God, we can expand our love to embrace even our enemies. Put another way: “Continue being merciful, just as your Father is merciful.”​—Luke 6:36.

As Jesus continues his sermon, he urges his listeners: “Take care not to practice your righteousness in front of men to be noticed by them.” Jesus condemns a hypocritical show of godliness, adding: “When you make gifts of mercy, do not blow a trumpet ahead of you, as the hypocrites do.” (Matthew 6:1, 2) It is better to give gifts of mercy in private.

Jesus next says: “When you pray, do not act like the hypocrites, for they like to pray standing in the synagogues and on the corners of the main streets to be seen by men.” Rather, he says: “When you pray, go into your private room and, after shutting your door, pray to your Father who is in secret.” (Matthew 6:5, 6) Jesus is not against all public prayers, for he himself offered such prayers. He is denouncing prayers said in a way to impress listeners and draw admiring compliments.

He counsels the crowd: “When praying, do not say the same things over and over again as the people of the nations do.” (Matthew 6:7) Jesus does not mean that repeatedly praying about the same subject is wrong. He is expressing disapproval of using memorized phrases “over and over again,” praying by rote. He then provides a model prayer that includes seven petitions. The first three recognize God’s right to rule and his purposes​—that his name be sanctified, that his Kingdom come, and that his will be done. Only after such matters should we make personal requests for our daily food and for forgiveness of sins, as well as requests not to be tempted beyond one’s endurance and to be delivered from the wicked one.

 How important should our possessions be to us? Jesus urges the crowd: “Stop storing up for yourselves treasures on the earth, where moth and rust consume and where thieves break in and steal.” How reasonable! Material treasures can and do perish, and our having them builds up no merit with God. Accordingly, Jesus next says: “Store up for yourselves treasures in heaven.” We can do this by putting God’s service first in life. Nobody can take away our good standing with God or its reward of everlasting life. So true are Jesus’ words: “Where your treasure is, there your heart will be also.”​—Matthew 6:19-21.

Emphasizing this point, Jesus gives an illustration: “The lamp of the body is the eye. If, then, your eye is focused, your whole body will be bright. But if your eye is envious, your whole body will be dark.” (Matthew 6:22, 23) When our eye functions properly, it is like a lighted lamp to our body. But to be such, our eye must be focused on one thing; otherwise, we could develop a mistaken estimate of life. Focusing on material possessions instead of on serving God would mean that our “whole body will be dark,” perhaps drawn to what is shady or dark.

Jesus then gives a powerful example: “No one can slave for two masters; for either he will hate the one and love the other, or he will stick to the one and despise the other. You cannot slave for God and for Riches.”​—Matthew 6:24.

Some hearing Jesus might be concerned about how they should view their material needs. So he assures them that they do not need to be anxious if they put God’s service first. “Observe intently the birds of heaven; they do not sow seed or reap or gather into  storehouses, yet your heavenly Father feeds them.”​—Matthew 6:26.

And what about the lilies of the field there on the mountain? Jesus notes that “not even Solomon in all his glory was arrayed as one of these.” What does this show? “If this is how God clothes the vegetation of the field that is here today and tomorrow is thrown into the oven, will he not much rather clothe you?” (Matthew 6:29, 30) Jesus wisely urges: “Never be anxious and say, ‘What are we to eat?’ or, ‘What are we to drink?’ or, ‘What are we to wear?’ . . . Your heavenly Father knows that you need all these things. Keep on, then, seeking first the Kingdom and his righteousness, and all these other things will be added to you.”​—Matthew 6:31-33.

The apostles and other sincere ones want to live in a way that pleases God, but that is not easy in their circumstances. Many Pharisees, for example, are critical, harshly judging others. So Jesus admonishes his listeners: “Stop judging that you may not be judged; for with the judgment you are judging, you will be judged.”​—Matthew 7:1, 2.

It is dangerous to follow the lead of the overly critical Pharisees, as Jesus illustrates: “A blind man cannot guide a blind man, can he? Both will fall into a pit, will they not?” Then how should Jesus’ listeners view others? Not with a critical eye, because that would be a serious offense. He asks: “How can you say to your brother, ‘Brother, allow me to remove the straw that is in your eye,’ while you yourself do not see the rafter in your own eye? Hypocrite! First remove the rafter from your own eye, and then you will see clearly how to remove the straw that is in your brother’s eye.”​—Luke 6:39-42.

This does not mean that the disciples are not to make any judgments at all. “Do not give what is holy to dogs nor throw your pearls before swine,” Jesus urges them. (Matthew 7:6) Truths from God’s Word are precious, like figurative pearls. If some people act like animals, showing no appreciation for these precious truths, the disciples should leave them and seek ones who are receptive.

Returning to the subject of prayer, Jesus stresses the need to persist in it. “Keep on asking, and it will be given you.” God is ready to answer prayers, as Jesus emphasizes by asking: “Which one of you, if his son asks for bread, will hand him a stone? . . . Therefore, if you, although being wicked, know how to give good gifts to your children, how much more so will your Father who is in the heavens give good things to those asking him!”​—Matthew 7:7-11.

Jesus then sets out what has become a famous rule of conduct: “All things, therefore, that you want men to do to you, you also must do to them.” Should not all of us take to heart and apply that positive exhortation in our dealings with others? Doing so, however, may be challenging, as revealed by Jesus’ instruction: “Go in through the narrow gate, because broad  is the gate and spacious is the road leading off into destruction, and many are going in through it; whereas narrow is the gate and cramped the road leading off into life, and few are finding it.”​—Matthew 7:12-14.

There are those who would try to divert the disciples from the way leading to life, so Jesus warns: “Be on the watch for the false prophets who come to you in sheep’s covering, but inside they are ravenous wolves.” (Matthew 7:15) Good trees and bad trees can be recognized by their fruits, Jesus notes. It is similar with people. Thus, we can recognize false prophets by their teachings and actions. Yes, Jesus explains, it is not simply what a person says that makes him his disciple but also what he does. Some people claim that Jesus is their Lord, but what if they are not doing God’s will? Jesus says: “I will declare to them: ‘I never knew you! Get away from me, you workers of lawlessness!’”​—Matthew 7:23.

Concluding his sermon, Jesus declares: “Everyone who hears these sayings of mine and does them will be like a discreet man who built his house on the rock. And the rain poured down and the floods came and the winds blew and lashed against that house, but it did not cave in, for it had been founded on the rock.” (Matthew 7:24, 25) Why did the house stand? Because the man “dug and went down deep and laid a foundation on the rock.” (Luke 6:48) So more is involved than just hearing Jesus’ words. We must exert ourselves to ‘do them.’

What, though, about the one “hearing these sayings” but “not doing them”? He is “like a foolish man who built his house on the sand.” (Matthew 7:26) Rain, floods, and winds would cause such a house to collapse.

The crowds are astounded at Jesus’ way of teaching in this sermon. He does so as a person having authority and not as the religious leaders. Probably many of those who listened to him become his disciples.