1Corinthians 14:2For 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. When you pray in tongues,your spirit man is praying and you are uttering mysteries concerning matters which are hidden to your mind. Your spirit prays through the Holy Spirit and the Holy Spirit knows all the important things which concern you. Praying in your own language will limit you, you will say all that you know with your mind in two minutes, yet there are spiritual mysteries and secrets that you don't know. This prayer is very important, if you are born again and still can't speak in tongues, you can receive this blessed gift right now. Just say oh Lord, you said in your Word that “these signs shall follow them that believe, in my name shall they cast out devil's, they shall speak with new tongues” and now I receive the gift of tongues which you promised to every believer and right away open your mouth and begin speaking in tongues. One of the advantages of praying in tongues, is that as you pray this way, you are arranging circumstances, events and people which God has divinely planned to be in your life for your favour, promotion and blessings. You will just stumble into blessings which have been placed at the right place at the right time by the Spirit of God. Another advantage of tongues is that when you pray this way, you are actually giving instructions to Angels to go take care of business in places beyond your physical reach. The prayer of tongues is the prayer which comes directly from your spirit, the words you release come purified by the Holy Ghost and anointed with power to cause changes.One other beautiful advantage of tongues, is that as you pray, the Holy Spirit imparts into you, the Spirit of Wisdom and revelation in the knowledge of him, that the eyes of your understanding may be enlightened, that you may know what is the hope of his calling and what are the glorious inheritance of the saints. when you are praying in tongues, the anointing of the Holy Ghost is staired, the first thing that will happen is that your body will begin to vibrate or shake, something like current of electricity will begin flowing all over your body, the anointing of the Holy Ghost will come upon you so mightily and suddenly you will be strengthened with might in your inner man. The next thing that will happen, is that your mind will begin receiving spiritual signals from higher realms, your mind will start receiving the interpretation of what you are saying from your spirit. When this happens, begin to release the interpretation in your own language, it will come forth as a prophetic utterance with the power to manifest in the physical. That’s Rhema from your spirit man