“If I pray in a tongue,
My spirit prays,
But my mind is unfruitful.”
ἐὰν γὰρ προσεύχωμαι γλώσσῃ, τὸ πνεῦμά μου προσεύχεται, ὁ δὲ νοῦς μου ἄκαρπός ἐστιν.
Paul said that if he prayed in a tongue (ἐὰν γὰρ προσεύχωμαι γλώσσῃ), his spirit was praying (τὸ πνεῦμά μου προσεύχεται), but his mind was unfruitful (ὁ δὲ νοῦς μου ἄκαρπός ἐστιν). Paul was clear that tongue speaking was okay because the individual human spirit was praying. However, it had the limitation that the mind, and here Paul makes it personal, was unfruitful. The congregation or assembly of Christians could not be intellectually involved with the tongue speaker. Even the tongue speaker, although clearly praying, was unable to communicate with his fellow Christians. Is your mind involved with prayer?