How I can show my friend that where it says “for all have sinned” it really does mean “all”? This is one verse he tries to switch to make it say “not all will sin.” to prove he doesn’t sin and therefore doesn’t need a Savior. I’ve prayed constantly for him on this matter, and I pray the Lord will guide him to truth.
Many unbelievers think they don’t need a savior because they think they don’t sin. This is a sign the Holy Spirit has not convicted them yet (John 16:8). But Romans 3:10 says, “There is no one righteous, not even one.” Then Romans 3:23 says, “For all have sinned and fall short of the glory of God.” The Greek word translated all means each, every one, all. There are no exceptions. 1 John 1:8-9 says if we claim to be without sin we deceive ourselves and the truth is not in us. If we confess our sins, He is faithful and just and will forgive us our sins and purify us from all unrighteousness.
The best thing to do is keep praying that the Holy Spirit will convict your friend of his sins and ask the Lord to save him. Praying like this is good and pleases God our Savior, who wants all men to be saved and to come to a knowledge of the truth (1 Tim. 2:3-4).