First of all, calling people who do not realize that there is a God a heathen isn't a way of drawing them to Him.. . Yes of course we should pray for them. The bible tells us that many are blinded and the prayer of a righteous man avails much. In fact, prayer will go much further than frustrated arguments.. . It is alot easier to see things when you have been set free through the spirit of God....by His son, Jesus Christ. But don't forget His word tells us to teach others and speak to them with humility, and respect.