According to author and preacher Francis Chan, some of the scariest words spoken are when people say they will wait to become a Christian. These people know the Gospel is true but would rather experience temporary pleasure and then give their life to Christ when they are older.
This sin is a form of idolatry and it is the most dangerous form of procrastination.
Why, you do not even know what will happen tomorrow. What is your life? You are a mist that appears for a little while and then vanishes. - James 4:14 NIV