"From that time Jesus began to preach, and to say, Repent: for the kingdom of heaven is at hand." Matthew 4:17
We tend to think of Jesus providing all the pretty, positive information that lifts us up and Jesus does, but Jesus also speaks to us about difficult decisions and hard to swallow truths. You don't have to be a Bible scholar to follow the simple requests/commands of Jesus. At some point in life and then again and again you need to repent, i. e., turn from the direction you are/were in (the direction of following after this world's system) and head the other way (toward a life filled with godliness and holiness.)
Jesus doesn't let the disciples carry the hard messages while He carries the easy to assimilate messages. Jesus knows that for you to grow in grace, you will have to find new direction and a new path and stay on it. He also knows, that, if for whatever reason you drift from that path, in order for you to get back on the right path, it will take a reason or a word or a consequence for you to make the change. Jesus supplies that word, repent/answer.
I know the though of repenting isn't treated with the utmost of respect in our generation. If you listen to enough diversified/alternate teaching you could almost fall into the trap of believing there are other ways of reconciliation to God. If you are looking for a loophole so that you can continue on the path that keeps you from a peaceful and approved relationship with God, you will have to make it up in your mind, because it doesn't exist. God already has in place every perfect response necessary for you to keep in line with the will of God for your life. It's real simple and it has always been real simple and it will always be real simple. Repent.
Note: Why does it bristle the hair when this issue comes up? We have become seasoned Christians. We have developed into a sort of sanctified gang. Together at or place of worship, we decide what is important (from the Bible of course) and should get emphasis and what is superfluous and should get little or no attention at all. If the whole agrees, wah lah, we have doctrine. There are entire denominations built upon this premise. Some have gotten so far off track that there is little to no essence of the gospel left. It is Jesus that says repent. And if I am going to adhere to anything (that Jesus says), I should be willing to adhere to everything that Jesus says. Why not study a little and find out why the concept of repentance is so important?