1 Corinthians 14:14-16

14For if I pray in a tongue, my spirit prays, but my mind is unproductive [because it does not understand what my spirit is praying].

15Then what am I to do? I will pray with the spirit [by the Holy Spirit that is within me] and I will pray with the mind [using words I understand]; I will sing with the spirit [by the Holy Spirit that is within me] and I will sing with the mind [using words I understand].

16Otherwise if you bless [and give thanks to God] in the spirit only, how will any outsider or someone who is not gifted [in spiritual matters] say the “Amen” [of agreement] to your thanksgiving, since he does not know what you are saying?