Why didn't God tell us He was coming?
Carol put it very well, naaji. Isaiah 9, Isaiah 53, and many others predict Jesus's coming. But, if you understand the covenant with Abraham that God made in Genesis, you will note that the punishment for breaking the covenent was to be paid ONLY BY GOD, and not by the people of Abraham. It was also a covenant that demanded payment and exactment of justice. The law that sin would mean (spiritual) death, needed to be fulfilled. No human can resurrect his own soul, That requires God. Yet, he is 100% just, so for justice to be done, the payment had to be collected. How do muslims pay for sin? By restitution, by ritual, by asking forgiveness, yet NONE of these things are sufficient. The penalty for sin is DEATH. The method of the Jews, Muslims, Hindu's, Buddists, Mormons...and all others falls short...ONLY GOD CAN RESTORE YOUR SALVATION, by paying the full dept for your sins.
When the covenant of splitting the animals in a ceremonial display indicating what would happen the one who broke the agreement...ONLY THE ESSENSE OF GOD passed through the split animals. In other words, God promised at that time to PERSONALLY PAY for the transgressions of His people. This is key to understanding salvation. God has promised to take upon His shoulders the punishment due us all.
Now, if Jesus were a man, He would not be able to be a serrogate sacrafice, since he was but human.....however, if he were God incarnate, He would be the PERFECT sacrafice once and for all for our sins, and salvation would be possible for all mankind.
Naaji, you have a limited understanding of Old Test prophesy, or you would be more familiar with the fact that the entire Old Test is a prelude to the coming of Jesus. It is from Him, and about Him.
This is the essence of the Gospel. This is what our Lord Jesus has commanded that we witness to all men. Please consider your need for Him very strongly.