Yes, God knows all about us. Yes, he created us. However, he did not "create" our behavior. Our behavior is sinful. The Bible says that everything we do, not just sin but also things we think are "good", are like filthy rags before God. This is because we are "fallen". Sin entered the world when Adam and Eve chose to rebel against God in the garden by eating the fruit of the tree of the knowledge of good and evil. God had explicitly told them not to yet they disobeyed Him and ate it anyway.
That one sin taints all of humanity (and even all of creation) to this day and it, along with our own sin, separates us from God. You see, God his perfectly holy and he cannot tolerate sin. He hates it. Not only that, because God is perfectly just, he must punish sin. That is where his righteous wrath comes in.
The Bible says that we (every person) have sinned and fall short of the glory of God. The bottom line is that we are sinners every one, our sin separates us from God who is holy and there is absolutely nothing we can do in and of ourselves to repair the relationship. In fact, we are so sinful that we don't even want to repair the relationship. We are lost.
But there is Good News!! God is perfectly just but he is also perfectly merciful. He has provided the means by which we can be reconciled to him! Not only that, he has provided it as a gift to us...for free. Why would he do this for us? Because he loves us. He loved us even when we, in our sin, hated him.
He sent his Son, Jesus Christ, to the earth to live as a man. Jesus was born without Adam's sin through the virgin birth and, this important, he lived a perfect life. Jesus never sinned. Not even once. He is the only person who ever lived who could approach God on his own merits.
But Jesus didn't abandon us to go live with God. That was not why he was sent. He was sent to pay the price for our sin. That's right. When Jesus was crucified on the cross, it wasn't just the physical pain he suffered. God unleashed all his horrible wrath on Jesus' spirit - the wrath the we deserved for our sin. Jesus took our place and all our sin was put on him. It was as if he had committed the sins, not us. In order for Jesus to take our place, he had to be perfect and he was.
This means that for those who believe in Jesus and accept him as their savior, their debt has been paid. God has wiped the slate clean. Not just for the past sins we have committed but also for every sin we will commit - all of it. Not only that, we get the righteousness of Christ. As far as God is concerned, it is as if we lived Jesus' perfect life.
In the New Testament of the Bible, we find two letters that Paul wrote to the Christians at Corinth. In the second of those letters, in the fifth chapter and the 21st verse, Paul explains Jesus' substitution for us this way:
"For our sake, he made him to be sin that knew no sin, so that in him we might become the righteousness of God."
That is the good news of the Gospel. God saved us by sending his Son to live a perfect life and die in our place. We are saved by believing in Jesus (by faith). When we admit our sin to God and our need of a savior, turn away from our sin (repent) and accept the free gift of salvation through Jesus Christ, we are immediately changed and our status before God is immediately changed. Our sins are no longer held against us by God and the Holy Spirit of God enters us. The Bible says that, at that moment, we are new creations.
Because we have been imputed with the righteous of Christ and our sins forgiven, when we die, we are able to enter heaven and spend eternity with God.
Please let me know if you have any other questions. I would be happy to answer them if I can.
If God is the creator of all that exists, why isn't He also the creator of our behavior?