“For anyone who speaks in a tongue does not speak to men but to God. Indeed, no-one understands him; he utters mysteries with his spirit” (1 Cor. 14:2).
The value of regularly speaking in tongues is the direct, spirit-to-Spirit connection one has with God in prayer. Please note that, “…If I pray in a tongue, my spirit prays, but my understanding is unfruitful” (1 Cor. 14:14). Clearly, one of the best ways to specifically engage one’s spirit in direct communion with God, Spirit-to-spirit, is through praying in tongues. We should even also sing in tongues (1 Cor. 14:15). This practice is often neglected because our minds feel irrelevant when we use it. As a result we tend to interrupt ourselves and minimise the use of this great gift in private worship. Thus we underutilise our spirit-man’s communion with God and by implication limit our spiritual sensitivity. This prayer language is more beneficial to believers who use it frequently, akin to Paul’s example (1 Cor. 14:18).
I urge you in your private devotions to ‘utter mysteries with your spirit’ often and to pray more with your spirit, and of course, with your mind too (1 Cor. 14:2,14,15).