Nearly every church requires repentance from sin of those who wish to be members. However, repentance is a greatly misunderstood command of God. It is also a very difficult command. Some have said it is the most difficult command in all the Bible. Sometimes the best way to learn the meaning of a word is first to look at what it is not before looking at what it is.
Many people think repentance is just being sorry for one's sins.
If one is sorry for the sins he has commited, it will cause him to repent of them. This shows they were very sorry for their sin of crucifying Jesus, but their sorrow for sin was not repentance. According to all the teaching of the Bible, repentance is a change of one's mind toward sin. It is produced by godly sorrow for one's sins. The result of this change of mind toward sin will be a change of life.