What is a sin unto death according to the bible?[ I John 5:16]

I asked a self-acclaimed deeper life zealous pastor like 7 years ago and up till now he never returned just as NLanders have veiewd this thread but none refused to reply, where are all the nairaland pastors, are they on thre run too?
Sin umto death obviously points to the fact that Sin is in two classes; if you read on you find out John also speaks about praying for one who has fallen into the sin that DOES NOT lead to death and forbids us tp pray for one who has fallen into the Sin that LEADS to death see ref below:
16If anyone sees his brother commit a sin that does not lead to death, he should pray and God will give him life. I refer to those whose sin does not lead to death. There is a sin that leads to death. I am not saying that he should pray about that. 17All wrongdoing is sin, and there is sin that does not lead to death.
This actually one of the scriptural support for the classification of sin as Mortal or Venial, Heaven, Hell (a state, where a soul can not help itself and cant be helped anyone else becuase it has sin that leads to death) and purgatory (a state, where a soul that has sin that does not lead to death, cant help itself but can be helped by other people's prayers)in the Roman Catholic teaching.

1 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.

Sin unto death is a matter for spiritualy mature people. maybe thats why nobody wants to comment. it is an in house matter not for umbelievers.
Sin unto death is a Spiritual sin that can not be forgiven. The individual is damned forever and can never be saved again. Some call it unpardonable sin. Some people have wondered if they had committed the sin. If you are wondering so ,it only means you have not commited it. This sin cant be commited by mistake, it cant be commited by baby christians,it can only be commited by people that have been very matured as christians .It is an outright denial of the lordship of christ.

Hebrews 6:4-6
For it is impossible for those who were once enlightened, and have tasted of the heavenly gift, and were made partakers of the Holy Ghost, [5] And have tasted the good word of God, and the powers of the world to come, [6] If they shall fall away, to renew them again unto repentance; seeing they crucify to themselves the Son of God afresh, and put him to an open shame.

Hebrews 10:29
Of how much sorer punishment, suppose ye, shall he be thought worthy, who hath trodden under foot the Son of God, and hath counted the blood of the covenant, wherewith he was sanctified, an unholy thing, and hath done despite unto the Spirit of grace?

For such a person you dont need to pray for him or preach to him because his conscience has been harden demonically.

Matthew 12:31
Wherefore I say unto you, All manner of sin and blasphemy shall be forgiven unto men: but the blasphemy against the Holy Ghost shall not be forgiven unto men.

Those who criticise men of God unecesarily on nairaland should watch it, because they dont know the spirit that is pushing them. I didnt say they are damned o. because many of them are just expressing their ignorance.

only a mature christian can commit. not all these ignorant attackers

Hebrews 6:4-6
For it is impossible for those who were once enlightened, and have tasted of the heavenly gift, and were made partakers of the Holy Ghost, [5] And have tasted the good word of God, and the powers of the world to come, [6] If they shall fall away, to renew them again unto repentance; seeing they crucify to themselves the Son of God afresh, and put him to an open shame.

Hebrews 10:29
Of how much sorer punishment, suppose ye, shall he be thought worthy, who hath trodden under foot the Son of God, and hath counted the blood of the covenant, wherewith he was sanctified, an unholy thing, and hath done despite unto the Spirit of grace?

These passages are simply self-explanatory; there is no mention of sin unto death, rather it is said if they "fall away" meaning leave thw Faith they once savoured coming back to it would be impossible, just like what became of Lucifer, who fell from a high level of grace.

Matthew 12:31
Wherefore I say unto you, All manner of sin and blasphemy shall be forgiven unto men: but the blasphemy against the Holy Ghost shall not be forgiven unto men. There is a background to this quote; The Pharisees openly ascribed a miraculous work of Jesus to the Devil; The saving power of God they rejescted against their own
reason.

Christ spoke here of all manner of sin, meaning sin are in categories.
Obviously since the the Holy Spirit is the very principle of sanctification any sin against Him, which basically IS about refuting his saving power can not be forgiven since the soul has fallen into the state where he can not even access the mercy of God

It is very risky to complicate plain matters or do guesswork at spiritual things that is beyond ones understanding; cos it makes one to henceforth interprete every part of scripture from that viewpoint.

49cents:

Hebrews 6:4-6
For it is impossible for those who were once enlightened, and have tasted of the heavenly gift, and were made partakers of the Holy Ghost, [5] And have tasted the good word of God, and the powers of the world to come, [6] If they shall fall away, to renew them again unto repentance; seeing they crucify to themselves the Son of God afresh, and put him to an open shame.

Hebrews 10:29
Of how much sorer punishment, suppose ye, shall he be thought worthy, who hath trodden under foot the Son of God, and hath counted the blood of the covenant, wherewith he was sanctified, an unholy thing, and hath done despite unto the Spirit of grace?

These passages are simply self-explanatory; there is no mention of sin unto death, rather it is said if they "fall away" meaning leave thw Faith they once savoured coming back to it would be impossible, just like what became of Lucifer, who fell from a high level of grace.

Matthew 12:31
Wherefore I say unto you, All manner of sin and blasphemy shall be forgiven unto men: but the blasphemy against the Holy Ghost shall not be forgiven unto men. There is a background to this quote; The Pharisees openly ascribed a miraculous work of Jesus to the Devil; The saving power of God they rejescted against their own
reason.

Christ spoke here of all manner of sin, meaning sin are in categories.
Obviously since the the Holy Spirit is the very principle of sanctification any sin against Him, which basically IS about refuting his saving power can not be forgiven since the soul has fallen into the state where he can not even access the mercy of God

It is very risky to complicate plain matters or do guesswork at spiritual things that is beyond ones understanding; cos it makes one to henceforth interprete every part of scripture from that viewpoint.

You have to understand that sin unto death is not talking about ceasation of life or physical death.

Genesis 2:17
But of the tree of the knowledge of good and evil, thou shalt not eat of it: for in the day that thou eatest thereof thou shalt surely die.

Question: did Adam die that day? NO and YES . No he did physiscally die, but yes he died that day spiritually , Spiritual death is separation from God.

Romans 6:23
For the wages of sin is death; but the gift of God is eternal life through Jesus Christ our Lord.

Ephes. 2:5
Even when we were dead in sins, hath quickened us together with Christ, (by grace ye are saved

So sin unto death does not mean the person will fall down to die. It is a separation from God. (apostacy). When a man come to a place where he has to deny his faith, deny That Jesus is lord, Deny the power of God. A man that has witnessed miracles and supernatural now claim they are of the devil, attribute the power of God to satan. Jesus call its blasphemy against the holyghost.

pastor2009:
What is a sin unto death according to the bible?[ I John 5:16]

sin unto death is apostasy...

I'll try explain later by God's grace