How do you work with someone who is without the faith that you are trying to convert? Do you approach them harshly and tell them how they are going to Hell? I hope not, because you will not help people to repent with that approach (especially not today). What is not known by many people today is that every Catholic has the ability to lead someone to the faith. You do not need a master's degree to know that Jesus is risen from the dead, is willing to forgive the penitent, and that He fully gives Himself to us in the Eucharist. The beauty of these truths are enough to lead someone else to the faith. So then, as St. Thomas Aquinas said it so well: To convert somebody go and take them by the hand and guide them.