Where does it say in the Bible that the devil trembles when the weakest of saints pray?

The devil trembles because remember, He(Christ Jesus) that is in us is stronger than the one out in the world(devil) 1Jhon 4:4. We are more than conqueres in Christ Jesus. (Romans 8:37). It doesn't. But consider two important Biblical concepts. Firstly, the Devil is a creature. As a creature he is not omni-present (everywhere), or omniscient (all knowing). Therefore, he is not aware of what every saint (in the Biblical sense, not the Roman Catholic sense) is praying. Secondly, when it comes to what we might loosely call spiritual warfare it is not the spiritual strength of the one praying that makes a prayer powerful or weak - the power of prayer has more to do with who is being prayed to than who is praying. Therefore, it is a Biblically false concept to think of the "weakest saints" when it comes to prayer. The terms weak and strong are not applied to Christians in The Bible according to how they pray. Rather, these terms are used to distinguish Christians over matters of freedom and conscience. Finally, too many Christians are intimidated by the Devil. The Bible reveals that he is a defeated foe who has been "disarmed" by Christ (Colossians 2:15). Therefore, we should not concern ourselves with "praying against" the Devil (or anything for that matter), but rather we should focus our praying on glorifying God.