They say that practice makes perfect, and here on Ask you'll find that you get many chances to practice getting your ideas across to folks who disagree with you. If you get bored some time, you can practice your technique on me anytime you see me kickin' around the site. I figure that if you can convince ME of the existence of your so-called "God", then you've got a pretty decent shot at convincing just about ANYone. Go ahead, hit me with your best shot ;)
Ask him how was the universe created, and how were organisms able to create humans and evolutionize to what humans are now, think about it, there is no way something could've been created without the beginning of something
It is much more difficult to convince anybody of anything than most people realize. Those who were raised to believe in God tend to continue believing in God, regardless of any evidence to the contrary. This is true not only for the Christian God, but also for Muslim, Jewish, Hindu, etc. Gods. Those who were raised to doubt in God and those who continue on to higher education tend to continue to doubt in God regardless of any intervention.