Christ's Obedience

"Christ's complete obedience to the law is reckoned to us. Death is the reward of sin, and so we cannot be freed from death, but by the death of Christ (Heb. 2:14-15). Man cannot be freed from the condemnation of death until he has done all the law requires (Matt. 19:17). As man cannot keep all the commandments, it must be done for him by a surety. Christ not only obeyed all the commandments on behalf of man, but he also bore the penalty of death. But though we are freed from the penalty of death, we are still bound to obey the law. Yet that obedience is not to gain acceptance with God, but rather it is an expression of gratitude to God for our deliverance from death.
Why did Christ die? He died because the law demanded the death of a sinner, and Christ was the surety for sinners."

-John Owen, Communion With God, Pg. 122