2 Corinthians 7

Paul wrote to the Corinthians concerning false gods and the world -

"Wherefore come out from among them, and be ye separate, saith the Lord, and touch not the unclean thing; and I will receive you.
18 And will be a Father unto you, and ye shall be my sons and daughters, saith the Lord Almighty."  (New Testament | 2 Corinthians 6:17 - 18)

And then he followed that promise -

"HAVING therefore these promises, dearly beloved, let us cleanse ourselves from all filthiness of the flesh and spirit, perfecting holiness in the fear of God."  (New Testament | 2 Corinthians 7:1)

In my mind, suggesting that striving for holiness is a condition for His eternal blessings.  Striving for holiness requires true repentance.  Concerning his previous epistle, Paul teaches -

"I perceive that the same epistle hath made you sorry, though it were but for a season.
9 Now I rejoice, not that ye were made sorry, but that ye sorrowed to repentance: for ye were made sorry after a godly manner, that ye might receive damage by us in nothing."  (New Testament | 2 Corinthians 7:8 - 9)

Paul introduces true repentance in that it requires being sorry in a "godly manner".  He explains -

"For godly sorrow worketh repentance to salvation not to be repented of: but the sorrow of the world worketh death."  (New Testament | 2 Corinthians 7:10)

Godly sorrow or true repentance is that which leads to salvation.  Sorrow of the world is when we are sorry for getting caught.  It does not lead to repentance or striving for holiness.