Is this a sin unto death?

Isaiah 22:14 And it was revealed in mine ears by the LORD of hosts, Surely this iniquity shall not be purged from you till ye die, saith the Lord GOD of hosts.

Like the following?

I John 5:16 If any man see his brother sin a sin which is not unto death, he shall ask, and he shall give him life for them that sin not unto death. There is a sin unto death: I do not say that he shall pray for it.