"Prove by the way you live that you have really turned from your sins and turned to God. Don't just say, 'We are safe -- we are the decedents of Abraham.' That proves nothing. God can change these stones into children of Abraham. Even now the ax of God's judgement is poised. ready to sever your roots. Yes every tree that does not produce good fruit will be chopped down and thrown into the fire." Luke 3:8-9
This is an excerpt of John the Baptist's preaching. Not exactly a feel good message, but important enough to be included in the Scriptures. It seems that it is an age old battle, those who are identified with God, struggle to live their identity. The people in Noah's time had that difficult and perished in the flood. It seems that the words of Genesis 8 are true that humans will always struggle with sin. John the Baptist points out that sin, and the result of that sin, a fruitless life. It was painful to even write that, a fruitless life, I don't think anyone sets out to live a fruitless life, however, that is what often happens.
This means that our goal, and drive should be not to simply claim identity with God through Jesus Christ, but life a life of fruit that shows that connection. We are to live a life that our actions lead our witness and our words are secondary.