John the Apostle
1 John 5:15BSB·traditional attribution

And if we know that He hears us in whatever we ask, we know that we already possess what we have asked of Him.

John Calvin Reformed @genevareformer

15 And if we know This is not a superfluous repetition, as it seems to be; for what the Apostle declared in general respecting the success of prayer, he now affirms in a special manner that the godly pray or ask for nothing from God but what they obtain.

Matthew Henry Presbyterian @wholebiblehenry

Here we have, I. A privilege belonging to faith in Christ, namely, audience in prayer: This is the confidence that we have in him, that, if we ask any thing according to his will, he heareth us, Jo1 5:14. The Lord Christ emboldens us to come to God in all circumstances, with all our supplications and requests. Through him our petitions are admitted and accepted of God.

Commenting on 1 John 5:14-17

John Gill Reformed Baptist @doctorgill

And if we know that he hear us,.... As it may be assured he does hear and answer all such persons that ask according to his will: whatsoever we ask, we know, or are assured, that we have the petitions that we desired of him: for as it is the nature of that holy confidence, which believers have in God, to believe whatever they ask...