Sounds like your friend needs prayer to remove the scales from his eyes.
He has to know that just quitting drugs wasn’t going to be the last attack the enemy would offer to fight for his soul.
Bad theology kills and destroys just as much (if not more) than drugs and other odious behaviors.
One thing I would offer is that all who are saved have different duties to the Kingdom of Heaven (not Earth). He may be confusing his calling by believing that Saving People will create a Heavenly Nation on Earth.
Verses against this:
Hebrews 11:14-16
2 Timothy 2:4
Matthew 6:19-21
Colossians 3:2
Philippians 3:19
Hebrews 10:34
1 Peter 1:4 (everything in the world will be burned up)
1 Peter 2:11
2 Peter 3:11-13
Philippians 3:20
very insightful. Thanks for the response. I will look these Scriptures up.