Will saved Christians take the mark of the beast/Antichrist? No, saved Christians will not take the mark, name, or number of the Beast, and here's proof from the Scriptures/the KJB:

To clarify, saved Christians cannot and will not take the mark of the beast or his number or name at all, because Jesus implied that believers [who the apostle Paul calls the elect (not the same as unbiblical, Gnostic, heretickal, wicked Calvinism heretickal twistings of the word "elect" and Calvinism unbiblical selective predestination heresy)] will be not deceived by the false prophets and false christs and thus will not be convinced or tricked into taking the mark of the beast. However the unsaved, all of whose names are not written in the Lamb's book of life, will take the mark fo the beast

If it were possible shows it is not possible for the saved people to take the Mark of the Beast.

Jesus said "(if it were possible)" before saying "they shall deceiue the very elect." which proves that believers (all of whom are the elect of God) will not be deceived by the false prophet or antichrist, will not worship the Antichrist or his image and will not take the mark, name, or number of the beast/the Antichrist:

The elect of Matthew 24:24 = saved believers/the saints (Colossians 1:1-2, 3:12)

Matthew 24:24 1611 KJB
For there shall arise false Christs, and false prophets, and shal shew great signes and wonders: insomuch that (if it were possible,) they shall deceiue the very elect.

Colossians 1:1-2, 3:12 KJB
[1] Paul, an apostle of Jesus Christ by the will of God, and Timotheus our brother,
[2] To the saints and faithful brethren in Christ which are at Colosse: Grace be unto you, and peace, from God our Father and the Lord Jesus Christ.
...
[12] Put on therefore, as the elect of God, holy and beloved, bowels of mercies, kindness, humbleness of mind, meekness, longsuffering;

At the same time, the unsaved, who many people who do not believe on the risen Lord Jesus Christ alone for salvation/ are not a saved believer, will take the mark, name, or number of the beast:
Revelation 13:1, 6, 8 1611 KJB
[1] And I stoode vpon the sand of the sea: and saw a beast rise vp out of the sea, hauing seuen heads, and tenne hornes, and vpon his hornes tenne crownes, and vpon his heads, the name of blasphemie.
...[6] And he opened his mouth in blasphemie against God, to blaspheme his Name, and his Tabernacle, and them that dwelt in heauen.
...[8] And all that dwel vpon the earth, shall worship him, whose names are not written in the booke of life of the Lambe, slaine from the foundation of the world.

Revelation 14:9-11 1611 KJB
[9] And the third Angel followed them, saying with a lowd voice, If any man worship the beast and his image, and receiue his marke in his forehead, or in his hand,
[10] The same shall drinke of the wine of the wrath of God, which is powred out without mixture into the cup of his indignation, and hee shall be tormented with fire and brimstone, in the presence of the holy Angels, and in the presence of the Lambe:
[11] And the smoke of their torment ascendeth vp for euer and euer. And they haue no rest day nor night, who worship the beast and his image, and whosoeuer receyueth the marke of his name.

Also, because saved believers are sealed by the Holy Ghost (Ephesians 1:30) and indwelled by the Holy Ghost (1 Corinthians 3:1, 16), saved believers will not and cannot take the Mark of the Beast:

And grieve not the holy Spirit of God, whereby ye are sealed unto the day of redemption.
Ephesians 4:30 KJB

👉 In whom ye also trusted, after that ye heard the word of truth, the gospel of your salvation: in whom also after that ye believed, ye were sealed with that holy Spirit of promise, which is the earnest of our inheritance until the redemption of the purchased possession, unto the praise of his glory.
Ephesians 1:13 - 14 KJB