How does one know in his heart that Islam is right religion? Please advice.

One must be first fully convinced that there is a right religion. He must accept that there is a right religion. And must be clear that God in his wisdom didn’t leave people on their own and that he sent messengers to guide them. Then compare religions on basis of teachings and look at which one is the true candidate to be the best religion. Then turn to God and ask for guidance. God will make it clear to them. It is through knowledge -we don’t want people to join the religion on basis of emotion but based on knowledge. First have the knowledge and then build the emotional commitment. Have all your basic questions answered; study other religions; which should mean that when you come into the religion there shouldn’t be the case that you didn’t know about other religions. So get an idea and then when you’re convinced in your heart, that’s the time to make the move.