God only being able to search the hearts,[1] hear the requests,[2] pardon the sins,[3] and fulfil the desires of all;[4] and only to be believed in,[5] and worshiped with religious worship;[6] prayer, which is a special part thereof,[7] is to be made by all to him alone,[8] and to none other.[9]
…then hear in heaven your dwelling place and forgive and act and render to each whose heart you know, according to all his ways (for you, you only, know the hearts of all the children of mankind)….Acts 1:24
And they prayed and said, “You, Lord, who know the hearts of all, show which one of these two you have chosen…”Rom. 8:27
And he who searches hearts knows what is the mind of the Spirit, because the Spirit intercedes for the saints according to the will of God.
O you who hear prayer,
to you shall all flesh come.
Who is a God like you, pardoning iniquity
and passing over transgression
for the remnant of his inheritance?
He does not retain his anger forever,
because he delights in steadfast love.
The Lord is near to all who call on him,
to all who call on him in truth.
19 He fulfills the desire of those who fear him;
he also hears their cry and saves them.
How then will they call on him in whom they have not believed? And how are they to believe in him of whom they have never heard? And how are they to hear without someone preaching?
Then Jesus said to him, “Be gone, Satan! For it is written,“‘You shall worship the Lord your God
and him only shall you serve.’”
To the church of God that is in Corinth, to those sanctified in Christ Jesus, called to be saints together with all those who in every place call upon the name of our Lord Jesus Christ, both their Lord and ours….
…and call upon me in the day of trouble;
I will deliver you, and you shall glorify me.
How then will they call on him in whom they have not believed? And how are they to believe in him of whom they have never heard? And how are they to hear without someone preaching?
Question 179, Westminster Larger Catechism