Jesus left heaven and came into this world to save sinners. Every miracle He performed testified that He had been sent by the Father. He healed lepers, blind men, the diseased, the demon-possessed, and even raised the dead.
Throughout His earthly life, He perfectly obeyed the Law of God in both thought and deed. His perfect righteousness merits eternal life for believing sinners. In Him is life.
"He became obedient unto death" (Philippians 2:8).
"By the obedience of one shall many be made righteous" (Romans 5:19).
"For he hath made Him to be sin for us who knew no sin" (2 Corinthians 5:21).
"In Him is no sin" (1 John 3:5).
"Who did no sin, neither was guile found in His mouth" (1 Peter 2:22).

The climax of Jesus' perfect obedience was His death on the cross. He died as a substitute for sinners, assuming the responsibility of their sin, and experiencing the wrath of God which was due them. His death paid in full the penalty of the broken Law for believing sinners. For us to pay the penalty of our own sins would take forever because we have offended an infinitely Holy God.
"He appeared to put away sin by the sacrifice of himself" (Hebrews 9:26).
"Who was delivered for our offenses" (Romans 4:25).
"In due time Christ died for the ungodly" (Romans 5:6).
"While we were yet sinners, Christ died for us" (Romans 5:8).
"Who his own self bare our sins in His body on the tree" (1 Peter 2:24).