Matthew 17:2-4

' At that time the disciples came to Jesus and asked, "Who is the greatest in the kingdom of heaven?" He called a little child and had him stand among them. And he said : "I tell you the truth, unless you change and become like little children, you will never enter the kingdom of heaven. Therefore, whoever humbles himself like this child is the greatest in the kingdom of heaven.'
Matthew 17:2-4

Jesus was telling his disciples that they, like you and me and every other human being, were sinners. The sins of Adam and Eve have made us this way, and there is nothing we can do about who we are except to accept it and humble ourselves in the face of the Father, God. We shouldn't try to be perfect because it will never happen. But Jesus asks us to do what's right, and when we don't, to ask for forgiveness. If you try to be perfect like God, then you are sinning even if you mean well. Because no one will ever be like God, and for us to accept that and repent for our sins is our true key to heaven.