In the Biblical worldview, there is a controversy going on about God’s character. The enemy to which Jesus refers in Matthew 13:28 (and is the serpent in Eden) has essentially asserted that the God of the Bible cannot be trusted with all that supernatural divine power. Lucifer’s request to become part of the ruling council of heaven was rejected (rightfully so, since Lucifer is a non-divine created being, and ruling a universe requires divine attributes). Lucifer rebelled in heaven, then brought his rebellion to earth.
Notice how the serpent tells Eve outright that God is lying to her about the consequences of eating the fruit. Can you trust a liar?
What was God supposed to do about the lies? What would you have done?
The answer to “Why did god create us” is that God needed to show in a microcosm the truth about what selfishness (or anti-love) does to the universe. He needed evidence that His way–the way of love–is the best way for all sentient beings and to maintain peace and joy throughout eternity in paradise. God allowed the controversy over His character to spill over onto this planet (he gave the serpent a platform from which to preach his accusations, and the human beings bought it), but only because it was going to be the way God resolved the entire issue. Instead of letting selfishness corrupt the entire universe, he was going to let it play out on a tiny planet that represented the universe. Essentially and ultimately, earth is an object lesson for the universe.
One of the questions stemming from this controversy is, why didn’t god just kill Satan? Well, think about how love would handle accusations. If one of your children started questioning your authority, and you killed him, what do you think your other children would think? “Wow. Billy was right. Dad is a harsh dictator who wields his power to kill those who question his governing. We better obey lest we get killed!” Now, the childrens’ allegiance, their obedience, is from fear, not out of love and respect.
God does not want fearful creatures as subjects. He wants loving children. He wants friends.
“When you tear out a man’s tongue, you are not proving him a liar, you’re only telling the world that you fear what he might say.” ― George R.R. Martin, A Clash of Kings
That is why God could not just kill Lucifer. You cannot meet accusations with violence. You must meet accusations with compelling evidence so that reasonable, sentient beings can draw their own conclusions about the matter.
Imagine a politician who has his political enemies killed. Is that because the politician is virtuous? Nobody would say so! And rightfully so! You let the ideas air out in the public square, and you leave the people free to decide.
The war that began in heaven was a political war. It was a war of words and ideas. The enemy knows God’s power and that God could not be defeated in a physical conflict. So he was going to have to resort to words. No, angels weren’t fighting a physical war against other angels. It was a political campaign by two parties: the party of love and the party of selfishness.
So, no, as a father, you cannot kill your rebellious child. (And you wouldn’t anyway!)
God could not just kill his enemies and be done with the matter.
Instead, you have to prove your love to your children, even the one questioning your authority.
How might you do that? How long might it take?
Look at what the God of the Bible accomplished through Jesus. He met the question about His loving character head-on. What does God do with all that power? He loves. He does not even defend himself physically from death at the hands of his “enemies” (angry, mentally-ill children). He lets himself be crucified to show that 1) he loves us, and 2) he can be trusted with all that power.
In contrast, what do selfish persons do with power? What did the enemy do when the Creator was powerless in his hands? They enslave. They kill. The selfish exercise their power to get what they want, even at the cost of others. God exercises His power for the good of His created children, even at the cost of Himself.
I know a lot of this is not embraced in modern Christendom. It is because of the aforementioned enemy. He has been and still is today sowing lies (weeds) and catching up a lot of human beings into the trap of doubting God’s love. However, in the end, all will be understood. Every knee shall bow and tongue confess, not because of coercion, but because God will have proven his love and all will embrace it. Even atheists. You will see all the evidence clearly presented of God working throughout human history to restore the broken human/God-of-love relationship that was severed in the garden by the enemy. You will see it all and be convinced of God’s love for you, and you will assent to his authority… not out of fear, but out of the love and trust gained from careful considering of all the evidence.