Shining Becky-
There are some scholars who believe that the New Testament books were all written decades after the life of Christ. But they base their opinions on their own bias (the circular argument) rather than on the evidence at hand. The actual evidence indicates that the three synoptic gospels (Matthew, Mark and Luke), Acts of the Apostles, and all of St. Paul's epistles were completed prior to 62 AD, with the other books completed within a few years. Here are two sources of evidence:
www.bible-researcher.com/muratorian.html
www.christiancadre.org/topics/dating_nt.html
As for secular historians of Jesus' time mentioning him in their accounts, you're operating under the idea that there was freedom of expression and freedom of speech, neither of which existed under the rule of imperial Rome. If a historian wanted to write history without being selected to be a lion's next meal, he toed the party line. This meant that the only person he recorded as being divine was the emperor himself.
As for Jesus' death being the means whereby God 'threw him away', you've adopted the attitude that his death was a victory for those who wanted to kill him. But it wasn't. Instead, it was a victory for Jesus himself, and even could be considered one of his miracles. The person who took Jesus' life was Jesus:
I am the good shepherd; I know my sheep and my sheep know me - just as the Father knows me and I know the Father - and I lay down my life for the sheep. I have other sheep that are not of this sheep pen. I must bring them also. They too will listen to my voice, and there shall be one flock and one shepherd. The reason my Father loves me is that I lay down my life - only to take it up again. No one takes it from me, but I lay it down of my own accord. I have authority to lay it down and authority to take it up again. This command I received from my Father. (The Gospel of St. John 10:14-18,NIV)
That's why the centurion was so shaken when he witnessed Jesus' death (Mark 15:39). That's also why Pilate was so surprised to hear that Jesus was already dead that he insisted on confirmation before he would release his body (Mark 15:42-45). The romans were so familiar with how long it took victims to die on a cross that they would even gamble on it. But Jesus had died days earlier than they expected him to. What they had wirnessed was not their victory, but instead his departure, and they realized it. He had fulfilled the mission, so it was time for him to return to God.
As for God's being cruel, we need to remember that we are not referrring to another human being when we are referring to God. God is a spirit, and is also The Author of Justice. And his justice demands absolute perfection. There's no such thing as being good enough or having the good deeds outweigh the bad ones; either we're perfect, or we're doomed. One sin in an entire lifetime is akin to having a million-gallon water supply, and then adding one drop of a highly toxic chemical into it, thereby rendering the entire water supply lethal.
But God is also compassionate. We cannot measure up to his requirements for righteousness if left to our own devices, and he knows that. So instead of writing us off as condemned, he himself did what we could not do, namely, made us perfect:
Now we know that whatever the law says, it says to those who are under the law, so that every mouth may be silenced and the whole world held accountable to God. Therefore no one will be declared righteous in his sight by observing the law; rather, through the law we become conscious of sin.
But now a righteousness from God, apart from law, has been made known, to which the Law and the Prophets testify. This righteousness from God comes through faith in Jesus Christ to all who believe. There is no difference, for all have sinned and fall short of the glory of God, and are justified freely by his grace through the redemption that came by Christ Jesus. God presented him as a sacrifice of atonement, through faith in his blood. He did this to demonstrate his justice, because in his forbearance he had left the sins committed beforehand unpunished - he did it to demonstrate his justice at the present time, so as to be just and the one who justifies those who have faith in Jesus. (Romans 3:19-26,NIV)
The righteousness which God requires of us is a righteousness which is equal to his own. And through the rescue mission which God himself laid the groundwork for, and then carried out with the help of his Son, Jesus Christ, he has enabled us to obtain that righteousness. We can't earn it through our own actions, because we're not perfect. But what we could not earn for ourselves God earned for us, and now is willing to give us if only we ask him for it.
And how are we to react? Would a person whose life was saved by another person go to that person's home, break his windows, slash the tires on his car, and set his house on fire? Of couse not. Likewise those of us who have accepted the righteousness which God has made it possible for us to obtain show our gratitude by endeavoring to do what he wants of us. We don't cooperate with him because we think that we're earning points with him through doing it. We don't cooperate with him because we think we can augment his righteousness by adding to it our own efforts. And we don't cooperate with him in order to hold on to our salvation; it was given freely, and it is ours. We cooperate with him because we are grateful for what he has done on our behalf. He didn't have to save us, but he chose to do so. And that's to his credit.
You may choose not to accept this. But you must also recognize that there are those of us who have.