And if we know that he hear us, whatsoever we ask, we know that we have the petitions that we desired of him.

People's New Testament

5:15 If we know that he heareth us. Hear us with open ears. Then we may know that we have what we ask. It will be granted.

Wesley's Notes

5:15 We have - Faith anticipates the blessings. The petitions which we asked of him - Even before the event. And when the event comes, we know it comes in answer to our prayer.

Jamieson-Fausset-Brown Bible Commentary

15. hear-Greek, "that He heareth us."

we have the petitions that we desired of him-We have, as present possessions, everything whatsoever we desired (asked) from Him. Not one of our past prayers offered in faith, according to His will, is lost. Like Hannah, we can rejoice over them as granted even before the event; and can recognize the event when it comes to pass, as not from chance, but obtained by our past prayers. Compare also Jehoshaphat's believing confidence in the issue of his prayers, so much so that he appointed singers to praise the Lord beforehand.

Matthew Henry's Concise Commentary

5:13-17 Upon all this evidence, it is but right that we believe on the name of the Son of God. Believers have eternal life in the covenant of the gospel. Then let us thankfully receive the record of Scripture. Always abounding in the work of the Lord, knowing that our labour is not in vain in the Lord. The Lord Christ invites us to come to him in all circumstances, with our supplications and requests, notwithstanding the sin that besets us. Our prayers must always be offered in submission to the will of God. In some things they are speedily answered; in others they are granted in the best manner, though not as requested. We ought to pray for others, as well as for ourselves. There are sins that war against spiritual life in the soul, and the life above. We cannot pray that the sins of the impenitent and unbelieving should, while they are such, be forgiven them; or that mercy, which supposes the forgiveness of sins, should be granted to them, while they wilfully continue such. But we may pray for their repentance, for their being enriched with faith in Christ, and thereupon for all other saving mercies. We should pray for others, as well as for ourselves, beseeching the Lord to pardon and recover the fallen, as well as to relieve the tempted and afflicted. And let us be truly thankful that no sin, of which any one truly repents, is unto death.