Many times over the years, I have struggled with the question of why God created the universe. The essence of my question is this: if God is self-sufficient (that is, not lacking anything or needing anything else to provide for Him), then what possible reason would He have to create anything outside Himself? Additionally, why did He create a universe where it was possible for Him to be rejected? Why not create a universe populated entirely with perfect beings?
One common answer I've heard is Love. God is Love, and so He desires to have relationship with others. Thus, He created the universe so that He could have relationship with His creation. This is an unsatisfying answer, however. First, it presumes that God is lacking something namely, relationship with others. Second, it overlooks the nature of the Trinity: God, from time eternal, has had perfect relationship within the Trinity itself. Thus, He did not lack relationship at any point and it is difficult to imagine that humanity could add any new dimension to the relationship which was lacking in the three persons of the Trinity.
Moreover, it doesn't answer the question of sin. If what God desires is relationship, then why allow for sin to exist? Why allow for broken relationships? The conventional answer here is that there cannot be true relationship without vulnerability without the possibility of betrayal. The idea is that God cannot have a relationship with a robot. Yet that logic fails when we consider the Trinity itself. Shall we say that God has the capacity to sin? When the Father and Son interact, is there even a hint of worry that one might betray the other? Certainly not! Even if we say that (in some abstract, distant sense) God could sin (as in, He has the power to do so), we would say absolutely that He cannot sin, as it violates His nature. If perfect relationship, without the possibility of betrayal, is workable within the Trinity, it seem almost certain that God could have had a similar relationship with created beings. In fact, when we consider our state in Heaven where we will no longer sin it seems quite clear that God can have true relationship with beings who do not have the capacity to sin!
So let's explore another possible answer. Perhaps, as some have claimed, the entire purpose of the universe is to further the glory of God. Perhaps the entire reason that we exist is so that God can have thinking beings outside Himself who have the ability to know Him, and to worship Him. This explanation is popular amongst Calvinists, and I count myself one of those; yet this explanation also fails to satisfy me.
First, it again trips over the self-sufficiency of God. If God wants something from us in this case, glory then it implies that there was something desirable which He would have lacked had He not created the universe. In some sense, God had to create the universe because He needs something which He can get from it.
This theory has a handy (though shocking) explanation for sin: sin exists because it increases God's glory. According to this theory, God allows sin to exist so that, through its existence, God could illustrate and exercise His holiness, judgement, and righteous anger. These are parts of God which exist, but which would have been idle and unknown to all of creation if not for the existence of sin. Without sin, God could not have show the majesty of His forgiveness and grace.
Yet can we really accept this explanation? Shall we say that there was something lacking in God's self-expression, which could not be expressed without the existence of sin? Isn't sin anathema to God? Shall we say that sin is somehow necessary to God? To quote Romans: Shall we go on sinning, so that grace may increase? May it never be!
But this explanation has one even more terrible flaw: it presumes the selfishness of God. If creation, and even sin, exist because their existence wins God worship from His creatures, then it means that all of our suffering on this Earth, and all of the suffering that people will endure in Hell, was ordained because God wanted something from us. God is not acting out of love: He is acting in of His own best interest.
Some say that this is perfectly just: God deserves worship, and He is entitled to do all He can to get it. Yet that does not seem to be the pattern of His interaction with us. God has repeatedly made Himself vulnerable to mankind: first in the Garden of Eden, continuing through all of the Old Testament, and most potently in the Incarnation. God did not reach down from Heaven and save us by remote control; instead He became one of us, carried our burdens upon His own soul, lived withing the limitations of our bodies, and walked in the ruins of what had once been His perfect creation. He submitted to flawed human parents, lived under hideous human government, and honored twisted human culture. He spoke and argued with a human voice, limiting His ministry to a single, tiny nation. He invited twelve broken men into His life, knowing that one would betray Him to death, all would desert Him, and his rock would deny Him in His greatest moment of need. On the Cross, He took up our sins, declaring Himself sinful though He had never committed any sin, and died the death that we deserved. God was separated from God, bearing the punishment that mankind deserved; the Trinity was rent apart, so that mankind could be drawn back into relationship.
Was it all real, or was it a hoax? Did Jesus really bear those burdens for us, or was He just playing His central role in a manipulative melodrama? In Gethsemane, was Jesus truly afraid for His life or was He just having the jitters, like an investor whose stock goes down for a day? Did Jesus submit to the Cross because He loved mankind and was obeying His Father, or because He knew it would pay off in the end?
I think that God's pain was genuine. I believe that God has given us the power to wound Him in real and lasting ways. While God has known all along exactly what we would do to Him there are no surprises for Him that doesn't negate the fact that what He offered to us was real relationship, and thus our betrayal is real as well. And so I believe that Jesus truly was motivated by love when He went to the Cross. He was not in it for Himself; He was not trying to win a prize. He was dying to Himself, and allowing His most precious relationship (with His Father) to be ripped apart for the sake of mankind.
In that context, I am quite comfortable also believing that Jesus could look ahead and see that glory would result. I am quite comfortable also believing that God calls us to worship Him: that is, after all, the only proper and fitting way in which our relationship with Him could work. But I simply can't accept the idea that God acts because He is motivated to maximize His own glory. It doesn't fit with what we know of His nature. Instead, when He calls us to worship Him, we should say that He does it for our sake so that we can have a completed relationship with Him rather than for His own. God is always looking out for others.
Yet this has brought us full circle. Given that the universe exists, and that there are people in it who have the capacity for sin, we can see how God launches Himself into the universe, suffering for our sake. But we still have not answered the original question: why did He create the universe in the first place, and why give us the power to sin at all? Can we find an explanation which doesn't imply that God was lacking something? Can we find an explanation which doesn't imply that He acted selfishly?
Here is my proposal: I think that creation was a net negative for God. That is, I believe that, while God will receive both relationship and glory from His created subjects, it does not make up for the pain that He must suffer on our behalf. To put it bluntly, God was better off before He made us.
This fits perfectly with what we know about God. We believe that God was entirely content within Himself, lacking nothing at all. All members of the Trinity knew each other completely (they even knew the holiness/judgement/wrath inside each other, without any need for sin to exist), and they loved each other perfectly. Nothing could be better than the eternal bliss that God experienced within Himself.
Yet God also was omniscient, and could look into the realms of possibility. There He saw the possibility of a broken race, created in His image, and yet tarnished by sin. He saw what it would take to love them what He would have to spend to save them. He saw all of the glory and delight which would come of it, and also saw that the Trinity itself would have to be rent asunder. But He also saw that they would love Him. They would delight to be His followers, and would exult in the wonder of their own existence, eternally in His presence.
God is love, so thoroughly and completely, that this plausible race of beings this hypothetical construct was more desirable to Himself than His own eternal bliss. And so He brought creation into being, and chose to spend Himself for their delight.
My answer doesn't explain why sin is necessary. I truly do not know. I have found no explanation which convinces me that this broken world is better than one where sin never existed. I can't explain why Hell exists, or why some people will go there for all eternity. But I feel quite confident that both exist for our own benefit: that God chose to make the world that way because it maximizes our own delight. Not His own.