'God created man for nothing else but happiness' (Jonathan Edwards, American preacher 1703-1758)
When someone is 'born again' they are forgiven and accepted by God. They will never be condemned. And a journey begins. It is not a journey of earning God's acceptance but it is the journey of living in the light of God's accpetance. We call it sanctification, which means to be made holy. It is the slow process of becoming more like Jesus. This process involves a transformation in the heart.
The Bible recognises that we will still struggle with sin all the days of this life and fail many times (1 John 1:8-2:2). Yet we are to keep on depending on God's forgiveness and upon his enabling (Phil. 2:13). The hymn-writer John Newton said of his growth in grace, 'I am not what I ought to be, but by the grace of God I am better than I used to be.' Over time, though we continue to live imperfectly, as we co-operate with God's grace we should be becoming more like Jesus. I hope that you will find this video helpful in understanding 'sanctification'.