As curiousdannii commented, "The cosmic child abuse argument is usually leveled against penal substitutionary atonement believers, not universalists." For clarity, it would be best to leave out all universal salvation ideas, for that is not necessary to give an answer. The bare bones of the question remain as: "the father sent his son to be tortured on a cross and also (for the sake of argument) descend into the deepest depths of Hell and endure further ineffable tortures there too. The problem: Doesn't this compromise both God's love and his justice? How was it loving for God to torture his own son? How was it just/fair for Jesus to take the punishment that we deserve?"
Those who do not grasp the total righteousness of God, and his requirement for cosmic justice, will never see the point of Christ's loving sacrifice on the cross. However, it is true to say that it was not 'fair' for Jesus to take the punishment that we deserve. Jesus chose to do that out of pure love for us helpless sinners.
Although God requires total, cosmic justice, he does not stick to cold-blooded justice that gives sinners only what they deserve - and all sinners deserve hell. So, for God to show mercy and love, he had to ensure that his perfect law was carried out on the cross, that everything done there fulfilled every legal requirement throughout the cosmos. And that is why the sinless Son of God submitted himself to bearing, in his body, the punishment we sinners deserve, in our place. He paid the price, as it were, because no sinner is able to do that for themself, let alone for others! As these scriptures state:
"None of them can by any means redeem his brother, nor give to God a
ransom for him (for the redemption of their soul is precious, and it
ceaseth for ever) that he should still live for ever, and not see
corruption... But God will redeem my soul from the power of the grave,
for he shall receive me" (Psalm 49:7-9 & 15).
"Therefore by the deeds of the law there shall no flesh be justified
in his sight: for by the law is the knowledge of sin. But now the
righteousness of God without the law if manifested... even the
righteousness of God by faith of Jesus Christ unto all and upon all
them that believe: for there is no difference for all have sinned and
come short of the glory of God; being justified freely by his grace
through the redemption that is in Christ Jesus, whom God hath set
forth. Jesus Christ is propitiation through faith in his blood, to
declare his righteousness for the remission of sins that are past,
through the forbearance of God. To declare at this time his
righteousness, that he might be just, and the justifier of him which
believeth in Jesus" (Romans 3:20-28).
"For when we were yet without strength, in due time Christ died for
the ungodly... God commendeth his love toward us, in that, while we
were yet sinners, Christ died for us... For the wages of sin is death,
but the gift of God is eternal life through Jesus Christ our Lord"
(Romans 5:6, 8 & 6:23).
"God, who is rich in mercy, for his great love wherewith he loved us,
even when we were dead in sins, hath quickened us together with Christ
(by grace are ye saved)... But now in Christ Jesus ye who sometimes
were far off are made nigh by the blood of Christ. For he is our
peace... that he might reconcile both unto God in one body by the
cross, having slain the enmity thereby" (Ephesians 2:4-16).
This destroys the Cosmic Child Abuse attack because God has satisfied his justice by showing himself entirely righteous at the cross. There was no other way to rescue sinners but by the sinless one becoming sin, in his own body, on the cross, and being punished for all sin. Having satisfied himself that sin had been punished, as his law demands, God then raised the Son from the grave, for the grave can only claim sinners, but the Son had not sinned. Now all who put their faith in the finished work of Christ on the cross stand cleansed before God. The Saviour and their Lord has been punished in their place, and God will not require punishment twice!
Given how nasty the Cosmic Child Abuse attack is, how it implies that God is cruel, unjust and unloving - when the exact opposite is the case - it has all the hallmarks of coming out of the pit. It twists and deceives. But that is why I have quoted so many scriptures, so anyone can read for themselves the righteous logic of the truth, and be amazed. For it was God, in Christ, being tortured by us, not God torturing Christ. And the Father and the Son did it to vindicate God's righteousness, and to show amazing love to undeserving sinners who will bow their knee in Jesus' name once the truth dawns on them. The Holy Spirit will lead sincere ones to that point of salvation.
