1 Corinthians 14:2,4,14,15

²For he who speaks in another language speaks not to men, but to God; for no one understands; but in the Spirit he speaks mysteries. ⁴He who speaks in another language edifies himself, but he who prophesies edifies the assembly. ¹⁴For if I pray in another language, my spirit prays, but my understanding is unfruitful. ¹⁵What is it then? I will pray with the spirit, and I will pray with the understanding also. I will sing with the spirit, and I will sing with the understanding also. 1 Corinthians 14:2,4,14,15