In 1 John 3:21-22, John writes:
21 Dear friends, if our hearts do not condemn us, we have confidence before God 22 and receive from him anything we ask, because we keep his commands and do what pleases him.
What does John mean by this? Is he saying God gives disciples carte blanche when it comes to them asking and Him answering? Understand, I’m not asking here if people believe this—I had someone assure me recently that “if you really believe, it will happen.” Fair enough, I know there are people who believe this. But is this what John is telling us in these words?
If we keep reading in 1 John, he brings the subject up again in 5:14-15. It seems to me that what he says there provides a baseline for the whole discussion of prayer.
14This is the confidence we have in approaching God: that if we ask anything according to his will, he hears us. 15And if we know that he hears us—whatever we ask—we know that we have what we asked of him.

If you just took v. 15 in isolation, then you have essentially the same thing as 3:21-22 and other texts. But v. 14 provides the qualifier I understand to be assumed in all of the passages—according to His will. Of course, this makes perfect sense (why would God answer a prayer that wasn’t according to His good and perfect will?). And because it’s so obvious, I think that also explains why it’s not mentioned in other passages about prayer. It’s not unlike if you handed some money to your teenager and told them they could buy whatever they wanted. You would assume from the context of your relationship with them that they understood they couldn’t spend it on anything illegal, immoral, dangerous, etc.
But to the point of John’s promise—how wonderful of a truth it is for the Christian to know that we can pray for anything and God will act. I have often (and I’m sure you have as well), been praying about something and just wasn’t sure what to ask for. It’s very assuring to throw up my understanding of the situation but then ask that God’s will (whatever that might be) prevail. It’s like marrying up—I feel like I’ve prayed up because I really didn’t know what to ask for but by asking for God’s will I know I asked for the right thing and I know it will be done.
I went into prayer confused and came out of prayer assured. That’s a good feeling and one Christians could have more of if they were more conscious of praying for God’s will and less busy telling Him what we think should happen.
This is the way Jesus taught us to pray (Matthew 6:9-10) and the way He prayed (Matthew 26:39,42,44).
For more on prayer and God’s will, click here.