Paul was accepted by Christians because:

• He did not preach a different gospel (Galatians 1:6-9).
• He went from violently opposing Christians to preaching that he had seen the risen Christ (Galatians 1:23-24).
• God moved in others to pay attention to him and receive his words as the very words of God (Acts 16:14, 1 Thessalonians 2:13).
• The other apostles did not oppose him, but concurred with him (Galatians 2:7-9).
• He was accompanied by signs and wonders. “The signs of a true apostle were performed among you with utmost patience, with signs and wonders and mighty works.” (2 Corinthians 12:12)
• Believers evaluated what he said according to existing scripture. “Now these Jews were more noble than those in Thessalonica; they received the word with all eagerness, examining the Scriptures daily to see if these things were so.” (Acts 17:11)
• He bore the marks of persecution, which he called the marks of Christ (Galatians 6:17; 2 Corinthians 4:7-12).