One standard anti-universalist argument can be summarily dismissed--the argument that universalism trivializes the urgency of embracing the Gospel. Does the prospect of spending long periods of Hell time in unimaginable conscious torment trivialize the Gospel? Please!
Are the ones sent to hell extra bad sinners?
They can be no worse that the 6-fingered giants before God had them exterminated. If these 2/3 are destined to die by the 7 vials and remain awake in hell for 1,000 years. Hell is a locked cage in a place called 'the Pit'. That is where all the 'sons of God' from Ge:6 are, except Satan, he shows up during the pouring out of those same vials. They are the ones sent to the fiery lake, the men in hell are released when the cage is unlocked at the Great White Throne judgment.
You cannot be a sinner and appear alive at that place.
Zec:13:8-9:
And it shall come to pass,
that in all the land,
saith the LORD,
two parts therein shall be cut off and die;
but the third shall be left therein.
And I will bring the third part through the fire,
and will refine them as silver is refined,
and will try them as gold is tried:
they shall call on my name,
and I will hear them:
I will say,
It is my people:
and they shall say,
The LORD is my God.
Re:19:21:
And the remnant were slain with the sword of him that sat upon the horse,
which sword proceeded out of his mouth:
and all the fowls were filled with their flesh.
Isa:65:12-15:
Therefore will I number you to the sword,
and ye shall all bow down to the slaughter:
because when I called,
ye did not answer;
when I spake,
ye did not hear;
but did evil before mine eyes,
and did choose that wherein I delighted not.
Therefore thus saith the Lord GOD,
Behold,
my servants shall eat,
but ye shall be hungry:
behold,
my servants shall drink,
but ye shall be thirsty:
behold,
my servants shall rejoice,
but ye shall be ashamed:
Behold,
my servants shall sing for joy of heart,
but ye shall cry for sorrow of heart,
and shall howl for vexation of spirit.
And ye shall leave your name for a curse unto my chosen:
for the Lord GOD shall slay thee,
and call his servants by another name:
Heb:12:6-8:
For whom the Lord loveth he chasteneth,
and scourgeth every son whom he receiveth.
If ye endure chastening,
God dealeth with you as with sons;
for what son is he whom the father chasteneth not?
But if ye be without chastisement,
whereof all are partakers,
then are ye bastards,
and not sons.
Heb:12:22-25:
But ye are come unto mount Sion,
and unto the city of the living God,
the heavenly Jerusalem,
and to an innumerable company of angels,
To the general assembly and church of the firstborn,
which are written in heaven,
and to God the Judge of all,
and to the spirits of just men made perfect,
And to Jesus the mediator of the new covenant,
and to the blood of sprinkling,
that speaketh better things than that of Abel.
See that ye refuse not him that speaketh.
For if they escaped not who refused him that spake on earth,
much more shall not we escape,
if we turn away from him that speaketh from heaven:
Re:7:9-17:
After this I beheld,
and,
lo,
a great multitude,
which no man could number,
of all nations,
and kindreds,
and people,
and tongues,
stood before the throne,
and before the Lamb,
clothed with white robes,
and palms in their hands;
And cried with a loud voice,
saying,
Salvation to our God which sitteth upon the throne,
and unto the Lamb.
And all the angels stood round about the throne,
and about the elders and the four beasts,
and fell before the throne on their faces,
and worshipped God,
Saying,
Amen:
Blessing,
and glory,
and wisdom,
and thanksgiving,
and honour,
and power,
and might,
be unto our God for ever and ever.
Amen.
And one of the elders answered,
saying unto me,
What are these which are arrayed in white robes?
and whence came they?
And I said unto him,
Sir,
thou knowest.
And he said to me,
These are they which came out of great tribulation,
and have washed their robes,
and made them white in the blood of the Lamb.
Therefore are they before the throne of God,
and serve him day and night in his temple:
and he that sitteth on the throne shall dwell among them.
They shall hunger no more,
neither thirst any more;
neither shall the sun light on them,
nor any heat.
For the Lamb which is in the midst of the throne shall feed them,
and shall lead them unto living fountains of waters:
and God shall wipe away all tears from their eyes.
Isa:65:16-19:
That he who blesseth himself in the earth shall bless himself in the God of truth;
and he that sweareth in the earth shall swear by the God of truth;
because the former troubles are forgotten,
and because they are hid from mine eyes.
For,
behold,
I create new heavens and a new earth:
and the former shall not be remembered, nor come into mind.
But be ye glad and rejoice for ever in that which I create: for, behold, I create Jerusalem a rejoicing, and her people a joy.
And I will rejoice in Jerusalem, and joy in my people: and the voice of weeping shall be no more heard in her, nor the voice of crying.