Jehovah’s people are united in worship of the one true God. Jehovah has entrusted the elders with the weighty responsibility of keeping the congregation clean. If a Christian commits a serious sin, Jehovah expects the elders to determine whether that individual can remain in the congregation. Among other things, they need to find out whether the person is truly sorry for what he did. He may claim to be repentant, but does he truly hate what he did? Is he determined not to repeat the sin? If bad associations led up to the wrongdoing, is he willing to cut off those associations? The elders prayerfully consider the facts in the light of the Scriptures, taking into account the wrongdoer’s attitude toward what happened. Then they decide whether the wrongdoer may remain in the congregation. In some cases, he must be disfellowshipped.​—1 Cor. 5:11-13. w22.02 5 ¶11-12

Whether we have been baptized for just a few days or for many decades, all of us want to have the kind of personality that Jehovah loves. To be that type of person, we need to control our thinking. Why? Because our personality is largely shaped by our thoughts. If we regularly think about what appeals to our fleshly desires, we will say and do bad things. (Eph. 4:17-19) On the other hand, if we fill our mind with good thoughts, we will more likely speak and act in a way that pleases our Father, Jehovah. (Gal. 5:16) However, we cannot stop all bad thoughts from entering our mind. But we can choose not to act on such thoughts. Before we get baptized, we need to stop speaking and acting in a way that Jehovah hates. That is the first and most important step in stripping off the old personality. To please Jehovah fully, however, we must also put on the new personality. w22.03 8 ¶1-2

It is no easy task for the elders to determine whether someone who has committed a serious sin is now truly repentant. Why not? The elders cannot read hearts, so they must rely on outward evidence that their brother has had a complete change of viewpoint toward his sin. They need to see evidence of genuine changes in the sinner’s thinking, feelings, and conduct. It might take the man considerable time to make the needed changes. To show that he is genuinely repentant, a disfellowshipped person would come to the meetings regularly and follow the elders’ counsel to have a good routine of prayer and study. He would also diligently avoid the circumstances that led to his wrongdoing. If he works hard to repair his relationship with Jehovah, he can be assured that Jehovah will forgive him fully and that the elders will restore him to the congregation. w21.10 6 ¶16-18