John Calvin on 1 Corinthians 12:6

6. One God that worketh. Where we use the word powers the Greek term is ἐνεργήματα, a term which contains an allusion to the verb worketh, as in Latin effectus (an effect) corresponds with the verb effectus (to effect.) Paul’s meaning is, that although believers may be endowed with different powers, they all take their rise from one and the same power on the part of God. Hence the expression employed here — worketh all things in all — does not refer to the general providence of God, but to the liberality that he exercises towards us, in bestowing upon every one some gift. The sum is this — that there is nothing in mankind that is good or praiseworthy but what comes from God alone. Hence it is out of place here to agitate the question — in what manner God acts in Satan and in reprobates.