Romans 9:33 KJV
As it is written, Behold, I lay in Sion a stumblingstone and rock of offence: and whosoever believeth on him shall not be ashamed.
This is a plain and simple promise and one that I know to be true through 33 years of trial as a Christian. "Whosoever believeth on Him shall not be ashamed."
There are many things a person may be ashamed of in their lives:
Words that should not have been spoken
Deeds that should not have been done
A person might look back in their life and think, "I wished I had not done that." But this I know to be true, no one ever says, I wished I had not believed on Christ. I wished I had not followed the Lord."
I can hear the cry of countless souls who, in eternal damnation, are ashamed they did not believe on Christ, but none will be ashamed they did.