1 John 5:16

If any man see his brother commit a sin, which is not a mortal sin, let him pray to God, who will grant him life, for such as do not commit a mortal sin. there is a sin unto death: in which case I do not enjoin any prayer to be made.

Treasury of Scripture Knowledge

Summary

Therefore pray not thou for this people, neither lift up a cry or prayer for them: for I will not hear them in the time that they cry unto me for their trouble.

Bible References

Pray

1 John 5:16
If any man see his brother commit a sin, which is not a mortal sin, let him pray to God, who will grant him life, for such as do not commit a mortal sin. there is a sin unto death: in which case I do not enjoin any prayer to be made.