Hi Frank,
First off,  I really enjoy reading your posts and respect your perspectives.  I am often enlightened by them.

I have not read Richard Wurmbrand's book, so I will share my thoughts and SCRIPTURES based on what you wrote.  To quote you, 
"...he asked his angel, which shocked him because of what he looked like, not angelic.  The Angel told him that he was a fallen angel that he repented."

Mormons believe an angel, Moroni, authored and buried the golden tablets from which the book of Mormon came from.   He appeared to Joseph Smith, telling him to translate them which became the book of Mormon.  This appearance by an angel came a few years after "the father and the son" appeared to him while he was praying asking "God" to tell him which church he should join.

Mormons wholeheartedly and unwavering believe "the father and the son" and an angel "Moroni" appeared to Joseph Smith.

Based on what you wrote, Richard IMHO was delusional when he saw his angel who told him he was fallen but repented.

I wonder why he asked his angel and not the Holy Spirit in the first place why he suffered so much.

In any case, 2 Peter 2:4 says this:  God did not spare the Angels that sinned.  

God DID NOT SPARE THE ANGELS THAT SINNED.

But cast them them down to hell, and delivered them into chains of darkness, to be reserved unto judgment.

 Jude 1:6:
And the angels which did not keep their first estate, but left their own habitation, He has reserved in everlasting chains under darkness unto the judgment of the Great day.

2 Corinthians 11:14:
Do not marvel for Satan himself is transformed into an angel of light.

Galatians 1:8
But though we or an angel from heaven preach another gospel unto you, other than what we have preached unto you, let him be accursed.

 And now for one of the most important scriptures in the Bible:

1 John 4:1:
Beloved , DO NOT BELIEVE EVERY SPIRIT, test the spirits whether they are from God  because many false prophets are gone out into the world.

Frank and all doves, there is no scriptural evidence fallen angels can repent.  If that was the case, the Satan himself could repent because he himself was once an angel.

 Just because we have given our lives to the Lord, Love Him, Love His Word and are looking for that Glorious day to be caught up to Him, does not mean we are not susceptible to deception.

Furthermore, I googled the question if fallen angels could repent. I wanted to be absolutely certain I covered all bases.  There was not one ounce of evidence this is possible.

I just pointed to several scriptures that prove this Angel this man saw and spoke with was not his guardian angel. If it was an angel he spoke with, he was fallen and a liar.  Most likely he was a demon telling him he was an angel.

Richard was either delusional or not right with God amidst his sufferings at the moment he asked his angel about his sufferings.  In any case, HE WAS DECEIVED!!!!  It can happen to many of us which is why we must never take off the Full Armour of God.

That said, if this person believed in Christ Jesus as his Lord and Savior, washed and cleansed in the Blood of the Lamb, he is truly saved.


Blessings and Peace to all,
Carol Garza