1cor14:2- For he that speaketh in an unknown tongue speaketh not unto men, but unto God: for no man understandeth him; howbeit in the spirit he speaketh mysteries.
A language is a system of communication in speech&writing used by people. If I want to cut you off from what I'm saying, all I need do is to change my language. The devil understands English and other earthly languages, but when we pray in our heavenly coded language, he becomes confused.
Whenever you are confused by the enemy, simply confuse your enemy by praying in the Holyghost. That's our vital means of cutting-off the devil in our prayers. Praying in tongues is a means of building one's faith. Jude1:20
Whenever you're down emotionally and the devil is deceiving you, speak in tongues. I personally believe every christian must be baptized in the HolyGhost with the evidence of tongue-speaking.
Jesus said in Mark 16:17- And these signs shall follow them that believe...THEY SHALL SPEAK WITH NEW TONGUES.
If you truly believe in Jesus according to the scripture above, then you must speak with new tongues.
Father, I receive fresh baptism of the HolyGhost In Jesus Name.