JMNT(i)
14 So if I am habitually praying in a language (or: speaking or thinking toward having goodness, with a tongue), my spirit (or: attitude; Breath-effect) is continually praying, yet my mind continues being unfruitful (or: my intellect is without fruit; = useless).
15 Which (or: What) is it, then? I will constantly pray (or: focus my thoughts on having goodness and speak toward things going well; [other MSS: I should pray]) in and by the spirit (or: with the Spirit; to the Breath-effect; for the Attitude), yet I will [other MSS: should] also repeatedly think and speak toward having good results in (or: pray by and with) the mind. I will continue striking the strings and sing (or: making melody) in and by the (or: = my) spirit (or: attitude; the Breath-effect), yet I will also habitually strike the strings and sing (make melody) in and by the (or: = my) mind.