Minsinterpretation. Wether intentional or unintentional...is by far the largest and single greatest reason as to the lack of understanding when it comes to Christian standings, and theology.
The same friend this year prayed to God when the Longhorns were down by 12 in the Rose Bowl, and promised God that he would go to church for a month if they won. It's become so shallow.
Do you feel that your friend is sincere? Do you feel his actions represent what a Christian, based on what the Bible teaches, would and should do? Don't let others mislead you when it comes to Christianity and other religions. If you want to take a stand on something, study it, learn it, and be educated in it. Amazing how noone would ever judge a book without reading it...or just by reading a random chapter here and there, yet this exact action is done with the Bible day in and day out, where just about every aspect is taken out of context, because people choose to let it be that way, they choose to be decieved.