I think this question is too complicated for a concordance-answer.
What happens if we apply The Circle I rambled about yesterday?
Prayer involves communication with God. And Jesus is God, fully and truly.
So, did Jesus hear people who didn't believe in him? Yes, of course. He didn't stumble around Galilee incapable of communicating with anyone who didn't believe in him.
This give us a boundary and an easy answer. But not a comprehensive one.
God hears and knows everything. So, on the face, it shouldn't surprise us to hear that God hears every prayer that ever gets prayed.
But there's a difference between hearing and "hearing."
And throughout the Bible, God seems to "hear" some prayers more than others.
Two in this category stand out to me:
1) Prayers of genuine repentance
2) Prayers that line up with God's secret will
This reality creates a boundary around our attempts to limit who can and can't get their prayers "heard," which is the typical approach to the question. Anyone can pray a prayer of genuine repentance (David, Nebuchadnezzer). Anyone can pray a prayer that lines up with God's secret will (Hagar, Balaam, the Ninevite king).
This organization - types of prayer rather than category of person - carries real-world help ... and challenge. Think about the difference this makes.
You don't have to hesitate to encourage someone to pray.
You don't have to wonder if God hears your prayer of repentance
You don't have to doubt your salvation if God doesn't do what you ask.
You shouldn't expect your status with God to get you a pain-free life
You shouldn't be shocked that God blesses the ungodly
You shouldn't be surprised if sometimes you feel unheard
Prayer stands for most of us as the most mysterious of the spiritual disciplines. We don't understand exactly how it works or exactly why it is asked of us. It threatens and collapses our systems, pushing the boundary of divine sovereignty and human responsibility, forcing us to veer between oversimplifying and looking away.
No one believed in God more than Jesus, God-in-the-flesh. But his prayers went "unheard," in a way. On the cross, he cried out, quoting Psalm 22, which reads:
My God, my God, why have you forsaken me?Perhaps Christ cried out without answer so that you and I and as many as would cry out to God might be heard.
Why are you so far from saving me,
So far from my cries of anguish?
My God, I cry out day by day, but you do not answer,
By night, but I find no rest.
How else can we explain the ease with which God hears us? We don't have to earn his hearing of a prayer of repentance. We don't have to convince him to do his will. Someone else has already done the earning, the convincing: Christ Jesus our Lord. And our prayers join with his.
There's a lot more we could talk about - what does "hearing" a prayer look like? what do we do when we don't feel heard? how do we talk to unbelievers about prayer? - but those will have to wait for another time.
What difference would it make in your prayer life if you really believed God heard you?