The wisdom of what a person says is in direct proportion to his progress in learning the Holy Scriptures – and I am not speaking of intensive reading or memorization, but real understanding and careful investigation of their meaning. Some people read them but neglect them; by their reading they profit in knowledge, by their neglect they forfeit understanding.

When You Have An Evil Thought, Do This! | St. Alphonsus Liguori
"When an evil thought is presented to the mind, we must immediately endeavor to turn our thoughts to God, or to something which is indifferent. But the first rule is, instantly to invoke the names of Jesus and Mary and to continue to invoke them until the temptation...