The Christian God

If God could create the whole universe by saying, "BE" and "IT WAS" then why couldn't He do the Same for the tiny littler sinner who is admitting his guilt and asking Him for forgiveness? Why couldn't He say to the person "Be forgiven" and he or she is forgiven? Why was the blood of an Jesus a necessity for this forgiveness?

This made me deeply review my Bible and try to find what was the essential necessity for salvation. The Jews and the Muslims never put anything in between them and their prayer to God so why did the Christians? There was nothing in between Adam and God, or Abraham and God, or Moses and God, or David and God, or Jesus and God! God had taught throughout the Bible that a person was individually responsible for his sins and that no one else could pay for or be penalized for them. Jesus preached repentance and telling people that their sins were forgiven before his crucifixion! So why all of a sudden was the blood of one martyr necessary for humanity to be forgiven?