2 For he who speaks in another language speaks not to men, but to God, for no one understands, but in the Spirit he speaks mysteries. 4 He who speaks in another language edifies himself, but he who prophesies edifies the assembly.
14 For if I pray in another language, my spirit prays, but my understanding is unfruitful.
15 What should I do? 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.