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.
There is an UNPARDONABLE SIN which people can commit. However, as this verse is pointing out, we have an advocate with the FATHER, JESUS, whom will cleanse us from ALL our sins if come to HIM and ASK forgiveness!