John 7:38-39. “He who believes in Me, as the Scripture has said, out of his heart will flow rivers of living water.” But this He spoke concerning the Spirit, whom those believing in Him would receive…
Jesus said that His words are spirit and they are life. (John 6:63).
Likewise, as you pray at length in tongues—not just a few syllables now and then—the words of life that you are uttering by the Holy Spirit begin to release the very life of God into your being, and pretty soon heaviness, discouragement and thoughts that try to oppress your mind begin to dissipate and are replaced by the thoughts of God that are contained within the Word of God! (See Isaiah 55:8-9).
Praying in the Spirit strengthens you with power in your inward man so that you have the spiritual “strength” necessary to lay hold of that which belongs to you in Christ, which brings blessing and prosperity to your entire being. (Eph 3:14-21). As you pray in tongues, the Holy Spirit guides you into all truth and takes that which belongs to Jesus and reveals it to you. (John 16:13-14).
The revelation that comes as you pray in tongues is one of the most effective ways in which you “find” or “discover” His words are that are life and health to all your flesh! (Proverbs 4:22).
This is the Biblical prosperity and success for the whole man—spirit, soul and body—that Joshua 1:8 and Psalms 1:1-3 promise to those whose delight is in the Word of God!