We do know that singing in the spirit is an overflow of love, joy and praise to God; and that it strengthens our spirit (1 Cor 14:2,4,17,18).

Paul is thankful to God that in his private devotions he prays in tongues (languages given by the Spirit) more than anyone else (1 Cor 14:18). What a powerful example for us to follow in our own daily life of devotion!