Did I give reasons for God being just?
You're clearly not at all following what I am saying. I have not said that those who don't believe in Christ will be saved and only lightly beaten. I do not know how you could come to such a conclusion.
Jesus makes the point in John that if a person doesn't believe in him, then he is condemned. Paul supports this by essentially saying that everyone who does not believe in Christ is a child of wrath. Jesus also tells us in Luke that unbelievers will face different levels of punishment, based on what they knew. (It's the opposite of what Paul tells believers in 1 Cor 3:12-15, that there will be different levels of reward, based on their works.) In Romans 1, Paul lays out the case that no one is without excuse as all should be seeking God based on what they see in creation. The writer of Hebrews tells us that we have one chance, while we're alive, to put our faith in Christ, because after we die, we face judgement.
So, for those who never heard the gospel, that's it. They face judgement and that judgement will determine what punishment they receive. All men are without excuse, although, like
Fastfredy0 , I think there will be exceptions based on mental capacity. God is just, and in the end, every single person will know that they got the judgement they deserved.
I reject all departures from Exclusivism. Salvation is possible ONLY "through Jesus Christ". Sinners in or out of the law perish when judged. There are no exceptions. But God is just for reasons few realize. Everyone who tried to follow the law or their conscience can be saved "through Jesus Christ":
12 For as many as have sinned without law will also perish without law, and as many as have sinned in the law will be judged by the law
13 (for not the hearers of the law are just in the sight of God, but the doers of the law will be justified;
14 for when Gentiles, who do not have the law, by nature do the things in the law, these, although not having the law, are a law to themselves,
15 who show the work of the law written in their hearts, their conscience also bearing witness, and between themselves their thoughts accusing or else excusing them)
16 in the day when God will judge the secrets of men by Jesus Christ, according to my gospel. (Rom. 2:12-16 NKJ)
Romans 2:16 gives the key many miss. Literally "διὰ Ἰησοῦ χριστοῦ" is "through Jesus Christ".
Look how the phrase is used in the NT:
NKJ Jn. 1:17 For the law was given through Moses, but grace and truth came through Jesus Christ.
NKJ Acts 10:36 "The word which God sent to the children of Israel, preaching peace through Jesus Christ-- He is Lord of all--
NKJ Rom. 1:8 First, I thank my God through Jesus Christ for you all, that your faith is spoken of throughout the whole world.
NKJ Rom. 2:16 in the day when God will judge the secrets of men by Jesus Christ, according to my gospel.
NKJ Rom. 5:21 so that as sin reigned in death, even so grace might reign through righteousness to eternal life through Jesus Christ our Lord.
NKJ Rom. 7:25 I thank God-- through Jesus Christ our Lord! So then, with the mind I myself serve the law of God, but with the flesh the law of sin.
NKJ Rom. 16:27 to God, alone wise, be glory through Jesus Christ forever. Amen 1>.
NKJ 2 Cor. 5:18 Now all things are of God, who has reconciled us to Himself through Jesus Christ, and has given us the ministry of reconciliation,
NKJ Gal. 1:1 Paul, an apostle (not from men nor through man, but through Jesus Christ and God the Father who raised Him from the dead),
NKJ Eph. 1:5 having predestined us to adoption as sons by Jesus Christ to Himself, according to the good pleasure of His will,
NKJ Eph. 3:9 and to make all see what is the fellowship of the mystery, which from the beginning of the ages has been hidden in God who created all things through Jesus Christ;
NKJ Phil. 1:11 being filled with the fruits of righteousness which are by Jesus Christ, to the glory and praise of God.
NKJ Tit. 3:6 whom He poured out on us abundantly through Jesus Christ our Savior,
NKJ Heb. 13:21 make you complete in every good work to do His will, working in you what is well pleasing in His sight, through Jesus Christ, to whom be glory forever and ever. Amen.
NKJ 1 Pet. 2:5 you also, as living stones, are being built up a spiritual house, a holy priesthood, to offer up spiritual sacrifices acceptable to God through Jesus Christ.
NKJ 1 Pet. 4:11 If anyone speaks, let him speak as the oracles of God. If anyone ministers, let him do it as with the ability which God supplies, that in all things God may be glorified through Jesus Christ, to whom belong the glory and the dominion forever and ever. Amen.
In other words, Christ's sacrifice bears the sins of these who tried to be righteous. But as is true of everyone, our righteousness isn't enough to be saved. Like us, God has reconciled them "through Jesus Christ" our LORD.
That is how God can judge the World, through Jesus Christ.
No one is judged apart from Christ, His sacrifice is applied to all these who died without Christ:
THAT is what Hebrews 9:22-28 also says, the eternal sacrifice of Christ is applied to everyone born since the foundation of the world and after men die, in the judgment Christ's sacrifice "bears the sin of many" who then repent and believe in His name. THESE eagerly wait for Christ's second coming for salvation:
22 And according to the law almost all things are purified with blood, and without shedding of blood there is no remission.
23 Therefore it was necessary that the copies of the things in the heavens should be purified with these, but the heavenly things themselves with better sacrifices than these.
24 For Christ has not entered the holy places made with hands, which are copies of the true, but into heaven itself, now to appear in the presence of God for us;
25 not that He should offer Himself often, as the high priest enters the Most Holy Place every year with blood of another--
26 He then would have had to suffer often since the foundation of the world; but now, once at the end of the ages, He has appeared to put away sin by the sacrifice of Himself.
27 And as it is appointed for men to die once, but after this the judgment,
28 so Christ was offered once to bear the sins of many. To those who eagerly wait for Him He will appear a second time, apart from sin, for salvation. (Heb. 9:22-28 NKJ)
Salvation of everyone happens EXCLUSIVELY "through Jesus Christ", even the salvation of Adam and Eve and everyone born brain dead, who died before the age of accountability....No one is saved apart from Christ in any other name.
This is why the gospel must also be preached to the dead, so they can be judged according to the judgment all men receive:
For this reason the gospel was preached also to those who are dead, that they might be judged according to men in the flesh, but live according to God in the spirit. (1 Pet. 4:6 NKJ)
God is just, there is no partiality with God. Everyone has an equal shot at being saved regardless their geographical, temporal, or physical circumstances.
This is why God sacrificed His only begotten Son, so the entire Kosmos (entire world of men leaving no one out) can be saved according to the same principle:
14 "And as Moses lifted up the serpent in the wilderness, even so must the Son of Man be lifted up,
15 "that whoever believes in Him should not perish but have eternal life.
16 "For God so loved the world that He gave His only begotten Son, that whoever believes in Him should not perish but have everlasting life.
17 "For God did not send His Son into the world to condemn the world, but that the world through Him might be saved.
18 "He who believes in Him is not condemned; but he who does not believe is condemned already, because he has not believed in the name of the only begotten Son of God.
(Jn. 3:14-18 NKJ)