One basic truth every believer must know is the fact that the Word of God cannot lie. “In the beginning was the Word, the Word was with God, the Word was God. The same was in the beginning with God. All things were made by Him; and without Him was not anything made that was made.
In Him was life and the life is the light of men. And the light shineth in darkness and darkness comprehended it not” (John 1:1-5 KJV) When you put the Word in your mouth, the devil will not be able to comprehend you. You become invincible to him. Rather than him becoming a problem to you, you will be a problem to him.
The scripture says that “God is not a man that He should lie, neither the son of man that He should repent: hath He said, and shall He not do it? Or hath He spoken, and shall He not make it good?”(Numbers 23:19 KJV)
In Hebrews 6:18, we understand that God has confirmed His promise by the two immutable things which make it impossible for Him to lie. In the first place, God’s Word is infallible. Yet He added an oath to it. An oath settles everything concerning anything. So, if you don’t believe His Word, you can believe the oath.
The book of Philippians chapter 4, verse 19 makes it clear that God shall supply all your needs according to His riches in glory by Christ Jesus. Since there is no shortage in heaven, you cannot suffer lack because you belong to the Kingdom that does not lack. If you are in Christ, your needs are already met. That should be your attitude. If you want to keep the devil’s mouth permanently shut, learn to declare what God has said about you. Don’t even wait until he attacks you. Declare it ever before the attack comes.