1 John 5:15

and if we know that He hear us, whatsoever we ask, we know that we have the petitions that we desired of Him.

The letter is finished, and the apostle now speaks his closing words, summarizing the principal points which he made in the body of the epistle: These things I wrote you in order that you might know that you have eternal life, since you believe in the name of the Son of God. The apostle is referring to everything that he wrote in this letter. His entire discussion had the aim and object of confirming the readers who have centered their faith in Jesus Christ, the Son of God, as their Savior, in the knowledge that they thereby were the possessors of eternal life. Faith has nothing in common with doubt and uncertainty, it is not a matter of personal opinion and feeling; it is glorious, certain knowledge based upon the Word of the Gospel. We know that we have eternal life through faith because the Scripture tells us so.

And this faith has another effect in us: And this is the boldness which we have toward Him, that, if we ask anything according to His will, He hears us. The prayers of the believers, the real prayers, are always heard, they never return unanswered. This cheerful assurance, this frank boldness, we hold. We enter into the very presence of the Lord with the calm certainty that our petitions will be heard as we make them in faith, in firm reliance upon the sonship which was given to us in Christ. It is self-evident that we, as children of God, will ask only such things as are in accordance with the will of our heavenly Father. In other words, we leave the answering of our prayers in His hands, knowing that His wisdom and mercy always find a way to give us what is best for us, regardless of the form in which we clothe our petitions. Note that His promise is not to grant all that we ask, but to hearken to our prayers: He answers in His own way.

This assurance should influence our entire attitude toward God: And if we know that He hearkens to whatever we ask, we know that we have the requests which we asked of Him. God always listens to the prayers of His children, reading their content even better than they intend it. We are sure of obtaining our requests, that which we are in need of, probably not always as our petition was worded, but always as it was best for us, and as we should have offered our prayer had we been wiser. Prayer is not a dictation to God to do thus and so, but a statement of our needs as we see them. And it is our heavenly Father who gives us more than our short-sightedness permitted us to know. If we have reached this point in our Christian knowledge, then our relation toward our heavenly Father will be unclouded by any lack of trust in Him.