Your objection is well-intentioned--Christianity means more than knowing the catechism. At the same time, God gave us heads as well as hearts, presumably because he wants us to use them. The man who refuses to think well about religion is condemned to think poorly about it. Jesus said he was the truth as well as the way and the life (Jn 14:6). Truth involves knowledge and obliges us to study to the extent our station in life permits. This is why Peter could write, "Make every effort to supplement your faith with virtue, virtue with knowledge" (2 Pt 1:5).