One cannot truly adopt the Christian faith without repentance, because the Christian faith is brought about through repentance and trusting in the Lord Jesus Christ as Saviour and Lord; with out repentance this is impossible. To repent of sin is to acknowledge our need of of a Saviour.
People avoid repenting of their sin for a number of reasons (1) Because Satan has blinded them to their need. (2) Pride - people are slow to admit that they are sinners and many would consider themselves a "good person", which brings about a third reason (3) Self-righteousness - they refuse to acknowledge any wrong in their lives and believe themselves to be better than others (such people are quick to point the finger).
As to the numbers of Christians (nominal) I should imagine there is a great number that are "religious" and have pehaps never truly repented and many that are unprepared in heart (but of course l would also like to add - that it is not for me to judge, unless of course it is a directive from the Holy Spirit i.e. a challenge as to a persons walk with the Lord).
