For me it’s simple.
Compare the lives of Jesus and Mohammed.
Jesus healed the sick, cast out demons, and raised the dead. He gave His own life as a sacrifice of atonement for the sins of the whole world.
Mohammed was a pirate, a warrior, a mass murderer, a torturer, an executioner, a thief, a liar, a rapist, a pedophile, a polygamist, an adulterer, a slave trader, a truce-breaker, a racist, a Jew-hater, an unspeakably cruel tyrant, and all-around genocidal savage. He delighted in the suffering of others.
Muslims would not disagree. They believe Jesus was a great Prophet and will assist the Mahdi in the last days.
He gave His own life as a sacrifice of atonement for the sins of the whole world.
Muslims say this is a lie of a corrupted Bible.
So how do you refute this?
Mohammed also rotted in the ground.