If God did not hear the prayers of the heathen, sinner, and even the false-christian there would be no real Christians.
But there is a line.
II Thessalonians 1:7 And to you who are troubled rest with us, when the Lord Jesus shall be revealed from heaven with his mighty angels,
8 In flaming fire taking vengeance on them that know not God, and that obey not the gospel of our Lord Jesus Christ:
9 Who shall be punished with everlasting destruction from the presence of the Lord, and from the glory of his power;
Even with that some false-christians teach that grace means nothing to obey. Tell Noah!
There is an exact Bible formula to measure exactly how many trinitarians will be saved. Simply count the number of souls saved outside of Noah's ark and multiply by one.