How Can a God who is All-Loving send his creatures to Hell to suffer forever?
While this is a worthwhile question to address, it is based upon an incomplete picture of who God is. Modern conceptions of the biblical God are often based upon a lop-sided presentation of who he is through watery preaching and superficial reflection upon the biblical text. We will often hear from pulpits, bible studies, and devotions that “God is love” (1 John 4:8), and this is quite true, however, this does not tell the whole story.
It is only upon taking the scripture in its broader context that we get a clearer and more complete picture of what God is like. Simply put, while we can agree with the clear biblical teaching that “God is love”, the bible’s descriptions of what God is like does not stop there. The bible also speaks of the righteousness of God (Psalm 119:137), the holiness of God (1 Peter 1:16), the justice of God (Deuteronomy 32:4), and the fact that he will punish sin. His perfect character requires him to act in ways that reflect his righteousness and justice, and hence, his perfect character requires him to punish unrighteousness of which, the only escape is placing trust in Jesus Christ for the forgiveness of sins.
Even when the judgment upon the sinner is diverted and their sins are forgiven, God’s righteous judgment is still satisfied through the expression of his wrath and justice. The sins of man never go unpunished since God as the righteous judge would be unrighteous in not judging sin. The great benefit experienced by the believer is that the righteous wrath and justice of God is poured out upon Jesus in their stead so that the believer’s punishment is paid for in the redeemer’s blood. Indeed, Jesus Christ is the propitiation for our sins (1 John 2:2) in that the wrath of God that we deserved is diverted and turned away being placed upon his person taking the full judgment that we deserve.
Now returning to our initial question. Yes, God is love (1 John 4:8), but God is also righteous, just, holy, and perfect. Those who are not in Christ pay the just penalty for their sins. Because all sin is sin against the infinitely holy God, the punishment and payment for those sins is eternal separation from God.
In physical terms, death is a separation from the body and soul. The soul either goes into the presence of God (2 Corinthians 5:8) or is separated from God awaiting final judgment. To be separated from God spiritually is also rightly described as death in that the soul is separated from the source of spiritual life. Hell is a place of eternal torment in which the soul that is there pays the penalty for their sins. Since this punishment is a punishment for sins committed against the infinitely holy God, the punishment is therefore eternal.
Furthermore, some have suggested that in hell, God’s restraints upon sin are removed thus resulting in sinners continuing in their sin and hatred towards God for all eternity hence contributing to the eternality of their punishment. Regardless of one’s position on this matter, the important thing is to recognize that while God is the most loving being in all of existence, he is also the most dangerous being in all of existence and should not be trifled with.
The answer to the above question is seen in an exploration of the various attributes of God and not the singling out of any one attribute. We must take God as he has revealed himself, not as we would like him to be. The same God which the Bible speaks “His loving kindness endures forever” (Psalm 136:1), is the same God in which we are told, “It is a fearful thing to fall into the hands of the Lord” (Hebrews 10:31).
 Propitiation refers to the “turning” away of wrath. To say that Christ is our propitiation is to say that he turns away the wrath of the Father and takes it upon himself. In so doing, the sinner is saved from eternal judgement.