You cannot fight the devil in the physical because he is a Spirit, you must create a Spirit or Spirits against him by your tongue.
If there is need to fight the devil with fire your tongue will create it, or if you want to use other weapons like Sword, Arrow, Hammer, and Brimstone against him, and your tongue will create them as you are praying. Though you may not see all the weapons and Spirits created by your tongue while praying, but I tell you the truth, they come alive as you pray with faith. You can only see the spiritual through the eyes of faith, you just need to believe and it will come to pass.
We create physical things with our hands and spiritual things with our tongue.
If you say to the blind receive your sight, it will be so if you doubt not. You can also tell the lame to arise and walk and he will do so if you doubt not.
Anytime the word spoken by man passes through the atmosphere, it produces pattern, which always last for years. The early scientist said that, every word spoken by man is registered in the atmosphere for six thousand years, while the bible says, “Men will give account of every spoken word remains till the day of judgment”.
Every word spoken by man remains in the atmosphere for as long as lifetime and it is easily readable by the spirit, both good and bad. When you proclaim an evil word against yourself, your Children, or somebody else the word is registered in the atmosphere serving as a command for the evil spirit to use in tormenting the person concern.
While proclaim good words on yourself and others serves as command for every good spirit to work on.
So care must be taken in the use of our tongue, not for cursing, abusing but for blessing.