If you think you are praying in the Holy Spirit and can understand the words as you pray, whether vocally or mentally, think again 1st Cor 14 "For if I pray in an unknown tongue, my spirit prayeth, but my understanding is unfruitful." "For if I pray in a tongue, my spirit prays, but my mind is unfruitful." Praying in the Holy Spirit and praying using the mind or intellect, are two separate events. Each has it's method and purpose. One cannot replace, join, or interchange with the other. They can however be done one after the other. Praying with the intellect is done vocally and mentally using English. Most Christians do it often. The prayer can be understood in the mind of the one praying and others who might hear it. The understanding is fruitful to the mind. Praying in the Spirit cannot be done with the human mind as the source, it will not understand it and cannot audibly or mentally reproduce the meaning of what the Spirit says: "my spirit prays, but my mind is unfruitful". "So what shall I do? I will pray with my spirit, but I will also pray with my understanding" Paul has defined two separate ways to pray, one in the Spirit, and another with the mind. Spirit-unknown tongue.........Human Mind-known tongue You cannot conclude with Spirit = known tongue You cannot conclude with Human Mind = unknown tongue He has not joined the two for a single method, but included both separate events as beneficial for a believer, one not above the other. He identifies what Praying in the Spirit is, Tongues. The only other way to pray is from your intellect. Your mind is not the same entity as your spirit. They have been in opposition since you got saved. Your Spirit is how you connect with God, who is spirit. Your mind is being renewed with continual repentance (changing your mind) until you have put on the full mind of Christ. Your mind goes out the window totally. This tells us until then, we ought to pray more in the spirit that is connected, than with a mind that is still open however small, to Satan's influence. There is no other definition available. Praying in the Holy Ghost is the same as Praying in Tongues. He further identifies the separations with singing in tongues, and singing from the mind. Paul did not write that the Holy Spirit would make him understand the prayer in Greek or Hebrew, so that he could then pray it with his mind or mouth. Romans 8 "In the same way, the Spirit helps us in our weakness. We do not know what we ought to pray for, but the Spirit himself intercedes for us through wordless groans." The Spirit does the praying, using groans that are not words we recognize, but vocalize. Groans are audible sounds. Holy Spirit prayers are a language made of utterances, groans, and unknown syllables that we sound out, and cannot understand. To say you can pray in the Holy Spirit without tongues, is saying your mind understands what the Holy Spirit prays when He intercedes. You would then be able to vocalize it with the mouth and others could understand in English, or German, or Spanish etc. That is in opposition to the biblical definition of Praying in the Holy Ghost. To presume silent prayers from the intellect in English are Holy Spirit prayers is a misunderstanding of scripture. If you say you can pray in the Holy Spirit using your mind or heart, you have taken the place of the Holy Spirit praying for you. Why? We should always pray with the mind, vocally and in silence, the prayers instructed by Jesus and in the New Testament. They use the mind and mouth in known languages. But inspired by the Holy Spirit is not the same as in the Holy Spirit. We are told to pray in the Holy Spirit. The unknown language is the only way. Jesus said He would send a helper. He helps our prayer life because we do not know what to pray. Jude "But you, beloved, building yourselves up in your most holy faith and praying in the Holy Spirit, keep yourselves in the love of God, waiting for the mercy of our Lord Jesus Christ that leads to eternal life." Some have a fear of tongues, that if they pray some jibberish it might be from the Devil. You will have to trust the Holy Spirit more than you fear Satan. Remember, Satan lies to the mind, he cannot speak to your spirit because your spirit is joined to the Holy Spirit, which is the Fathers Spirit. Satan cannot tempt God. There is for those who step out in faith great rewards.