16 If anyone sees his brother committing any sin except a deadly one, he will ask and obtain life for him—provided the sin is not a deadly one. There is such a thing as deadly sin; I do not say that a man should pray about that.
1 John 5:16 Cross References - Goodspeed
Matthew 12:31-32
31 Therefore, I tell you, men will be forgiven for any sin or abusive speech, but abusive speech about the Spirit cannot be forgiven.
32 And whoever speaks against the Son of Man will be forgiven for it, but whoever speaks against the holy Spirit cannot be forgiven for it, either in this world or in the world to come.
Mark 3:28-30
Luke 12:10
10 And anyone who speaks against the Son of Man will be forgiven for it, but no one who reviles the holy Spirit will be forgiven.
John 17:9
9 I have a request to make for them. I make no request for the world, but only for those whom you have given me, for they are yours—
2 Timothy 4:14
14 Alexander, the metal-worker, did me a great deal of harm. The Lord will repay him for what he did.
Hebrews 6:4-6
4 For it is impossible to arouse people to a fresh repentance when they have once for all come into the light and had a taste of the gift from heaven, and shared in the holy Spirit
5 and felt the goodness of the word of God and the strong influences of the coming age,
6 and yet have fallen back, for they crucify the Son of God on their own account, and hold him up to contempt.
Hebrews 10:26-31
26 For if we choose to go on sinning after we have so fully learned the truth, there is no sacrifice left to be offered for our sins,
27 but only the dreadful prospect of judgment and that blazing indignation which is to devour God's enemies.
28 Anyone who breaks the Law of Moses is put to death without any show of pity, on the evidence of only two or three witnesses.
29 How much worse a punishment do you think will anyone deserve who tramples the Son of God underfoot, and treats as worthless the blood of the agreement by which he has been purified, and outrages God's spirit of mercy?
30 For we know who it is that has said, "Vengeance belongs to me! I will pay back!" and in another place, "The Lord will be the judge of his people!"
31 It is a fearful thing to fall into the hands of the living God!
James 5:14-15
2 Peter 2:20-22
20 For if after men have escaped the corrupting influences of the world through the knowledge of the Lord and Savior Jesus Christ, they again become entangled in them and are overcome by them, their final condition is worse than their former one.
21 For it would have been better for them never to have known the way of uprightness than after knowing it to have turned their backs upon the sacred command with which they had been intrusted.
22 What has happened to them shows the truth of the proverb, "A dog returns to what he has vomited up, and a sow that has washed goes back to wallow in the mire."