I believe that it is easy to fall away from God if you do not have his word rooted deep on the inside of you, as humans we are unable to stop ourselves from falling inour natural state greater is he that is in me than he that is in the world, the word of God convicts and and gives us the ability to be more than conquerors. Keep the word deep in your heart so when the going gets tough you can put on the whole armour of God.