This is a great question. Why did Jesus have to suffer and die to forgive our sins?
The answer is not in the forgiveness of sin, but in the need to pay the debt for the sin. We incur a debt when we sin. Every sin incurs the same debt. It is death...eternal destruction...endless death, for the soul of man never dies. God's love for us is witnessed in that He willingly took on the flesh of a man for the purpose of becoming our substitute and dying the death we owe for our sin. It was His choice and now is His gift for all who will accept it.