Looking for more proofs to help a Christian friend see Prophet Muhammad (peace be upon him) as a true messenger

Assalamu alaikum, everyone. I’ve got this Christian pastor friend, and we’ve been having some deep chats about faith. He’s been inviting me to Christianity, but alhamdulillah, I’ve been able to share some points that made him think. We talked about concerns with Paul, questions about the Trinity, places where Bible stories don’t fully add up but Islam clears them up, and more. Now he’s actually starting to question his own beliefs. The main thing he’s stuck on is accepting Muhammad (peace be upon him) as a genuine prophet. I already brought up the 'comforter' reference and how Muhammad fit the prophecy about Abraham’s descendants ruling between the two rivers. He’s not dismissing these, but he’s not fully convinced yet, you know? I feel like I just need a little extra nudge to help him see the truth. Does anyone have other arguments or proofs that might click with a Christian? Please share whatever you got, jazakum Allahu khairan.