Not only can a christian commit the unpardonable sin it is only a christian who is able to commit the unpardonable sin.
How can I say that. Lets go take a look at Luke 21.
Verse 15.
English Standard Version
for I will give you a mouth and wisdom, which none of your adversaries will be able to withstand or contradict.
Berean Study Bible
For I will give you speech and wisdom that none of your adversaries will be able to resist or contradict.
King James Bible
For I will give you a mouth and wisdom, which all your adversaries shall not be able to gainsay nor resist.
Jesus says He will give you a mouth or words of wisdom to say that your adversaries are not going to be able to resist. This is where a christian might commit the unpardonable sin, we will cover that at the end.
Verse 16.
English Standard Version
You will be delivered up even by parents and brothers and relatives and friends, and some of you they will put to death.
Berean Study Bible
You will be betrayed even by parents and brothers and relatives and friends, and some of you will be put to death.
King James Bible
And ye shall be betrayed both by parents, and brethren, and kinsfolks, and friends; and
some of you shall they cause to be put to death.
Why would a parent a brother, sister other relatives, and friends deliver you up? Remember where this is taking place; In Jerusalem. Who will be setting in the temple at this time.
2nd Thessalonians 2:1-5
1Now we beseech you, brethren, by the coming of our Lord Jesus Christ, and
by our gathering together unto him,
2That ye be not soon shaken in mind, or be troubled, neither by spirit, nor by word, nor by letter as from us, as that the day of Christ is at hand.
3Let no man deceive you by any means: for
that day shall not come, except there come a falling away first, and that man of sin be revealed, the son of perdition;
4Who opposeth and exalteth himself above all that is called God, or that is worshipped; so that he as God sitteth in the temple of God, shewing himself that he is God.
5Remember ye not, that, when I was yet with you, I told you these things?
Mark 13:14 But when ye shall see the abomination of desolation, spoken of by Daniel the prophet, standing where it ought not, (let him that readeth understand,) then let them that be in Judaea flee to the mountains:
Satan, the Antichrist will be seated in the temple proclaiming to be God and hat is who you are going to be delivered up to.
These people that are delivering you up are thanking that they are bringing you to Jesus. They truly thank he is because they have been told Jesus comes before Satan to rapture us away. Your message is his is the Antichrist do not believe him so of course they are not going to like you.
Luke 21:17
English Standard Version
You will be hated by all for my name’s sake.
Berean Study Bible
And you will be hated by everyone because of My name.
King James Bible
And ye shall be hated of all
men for my name's sake.
Strong's Greek 3404:To hate, detest, love less, esteem less. From a primary misos; to detest; by extension, to love less.
Luke 21:18
English Standard Version
But not a hair of your head will perish.
Berean Study Bible
Yet not even a hair of your head will perish.
Berean Literal Bible
And no, not a hair of your head should perish.
King James Bible
But there shall not an hair of your head perish.
Mark 13:11-13
KJV
But when they shall lead
you, and deliver you up, take no thought beforehand what ye shall speak, neither do ye premeditate: but whatsoever shall be given you in that hour, that speak ye: for it is not ye that speak, but the Holy Ghost.
12Now the brother shall betray the brother to death, and the father the son; and children shall rise up against
their parents, and shall cause them to be put to death.
13And ye shall be hated of all
men for my name's sake: but he that shall endure unto the end, the same shall be saved.
ESV
And when they bring you to trial and deliver you over, do not be anxious beforehand what you are to say, but say whatever is given you in that hour, for it is not you who speak, but the Holy Spirit.
12And brother will deliver brother over to death, and the father his child, and children will rise against parents and have them put to death.
13And you will be hated by all for my name’s sake. But the one who endures to the end will be saved.
Verse 11. You are not to thank about what you will say, you are not to be anxious about it either. It will not be you speaking but the Holy Spirit that speaks through you.
Verse 12: You will be betrayed up to death.
Strong's Greek 2288: Death, physical or spiritual. From thnesko; death.
Hebrews 2:14 Forasmuch then as the children are partakers of flesh and blood, he also himself likewise took part of the same; that through death he might destroy him that had the power of death, that is, the devil;
Luke 21:18. But there shall not an hair of your head perish.
19In your patience possess ye your souls.
That is the promise
IF we allow the Holy Spirit to speak through us we will save our soul and death(Satan) can not take our lives(Spiritual, eternal live) God will not allow Satan to kill our physica body either. Mot a hair on your head will parish.
If we commit that unpardonable sin and open our mouths and we starting talking our words and not those of the Holy Spirit we have denied Him.
My opinion I do not thank that anyone of Gods elect at that point in time will commit this sin.