I read this today and found it helpful...
We know God is good, kind, patient, longsuffering, always willing to forgive. He is love personified, magnified, and exemplified (1 John 4:16). But God is also just, infinitely holy, and perfectly righteous. The Scriptures picture Jesus as both the Lamb of God (John 1:29) and the Lion of Judah (Rev. 5:5). Like a lamb, He is meek, gentle, a holy sacrifice for the sin of those who confess Him. Like a lion, His claws can tear the unrepentant to pieces.
It is this picture that reveals a first answer to the problem of hell: God's character demands it. While God's love, mercy, and grace are demonstrated in the atonement of Christ, other attributes demand equal authority and actually justify hell. What are these attributes?
Righteousness/Holiness. That God is righteous and holy means He always acts in accordance with those things He deems just and lawful. He cannot do anything less than what is right. God's great plan is ultimately to bring the universe back to perfect righteousness—back into harmony with His character. There are only two ways He can do that. One is by providing a way for sinners to return to righteousness—through the death, Resurrection, and power of Jesus Christ. In Christ He makes us new creatures (2 Cor. 5:17).
But what about those who do not seek righteousness, who desire darkness over light? There is a second option. God will confine such people in a place where they cannot affect or harm those who seek righteousness. That is hell.
Justice. The justice of God functions as a logical complement to His righteousness. His righteousness demands that He make things right. His justice demands that something be done about sin. Again, to bring about perfect justice for all the wrongs in the universe, God offers two options: to make payment for them Himself through the death of Jesus; or to require payment by the sinner. God cannot wink at sin, overlook it, or allow it to persist (Habakkuk 1:13; Psalm 5:4–6)
Omniscience. God's omniscience enables Him to know everything that is, was, shall be, and could be (Psalm 139; Isaiah 46:10). How does this attribute require a hell? An omniscient God must eliminate evil from His knowledge. One way is to forgive that evil and choose to forget it forever.14 God can actually "blot out" or eradicate His own knowledge on such an issue.
But what of those whom He has not forgiven because they have not accepted His forgiveness in Christ? God's only other option is to gather all the evil into one place and render it dead—separated from Him forever. That is hell. While God may be conscious of the evil in that place, He does not have to have contact with it or look on it ever again.
Love/Wrath. These two aspects of God's nature are linked together in the doctrine of hell. His love requires a hell because He must protect those He loves from the defilement of His enemies. His wrath calls for vengeance—that His enemies be punished for injuring, hating, and rejecting Him.
Nearly any aspect of God's character can be used to explain both heaven and hell. We have to take God and what His Word says about Him on His terms, not ours. Those who accept His grace and love but balk at the idea of justice or perfect holiness are guilty of folly.
By Mark R. Littleton—Discipleship Journal