Many people fall away from the faith because they're angry at God for a variety of reasons. We bring many of our problems upon ourselves by rejecting what God has planned for us!
Many extremely bad and sorrowful things happen to the best of people, and while we watch the innocent suffer, we must always remember one thing, and that one thing is that everything that is evil and unjust in this world is the result of sin, not God. Sin is man's disobedience to God. It is living outside of His will!
Don't be mad at God! Come home to Him!
The following is a video of Father Larry Richards speaking on Obedience to God: