It is Jesus’ obedience that saves us, not our own. “Therefore, as one trespass led to condemnation for all men, so one act of righteousness leads to justification and life for all men. For as by the one man’s disobedience the many were made sinners, so by the one man’s obedience the many will be made righteous” (Romans 5:18-19).
Christians should never think their works contribute to their justification or salvation in any way. Thankfully, here are twelve reasons why Jesus meant it when he said, “It is finished” (John 19:30).
1. Jesus—being true God and true human—was the perfect, once for all sacrifice for sin.
And the Word became flesh and dwelt among us, and we have seen his glory, glory as of the only Son from the Father, full of grace and truth. (John 1:14)
For Christ has entered, not into holy places made with hands, which are copies of the true things, but into heaven itself, now to appear in the presence of God on our behalf. Nor was it to offer himself repeatedly, as the high priest enters the holy places every year with blood not his own, for then he would have had to suffer repeatedly since the foundation of the world. But as it is, he has appeared once for all at the end of the ages to put away sin by the sacrifice of himself. (Hebrews 9:24-26)
2. Only Jesus kept the law fully—he was the true Son of Israel who loved God and his neighbor perfectly.
“Do not think that I have come to abolish the Law or the Prophets; I have not come to abolish them but to fulfill them.” (Matthew 5:17)
For our sake he made him to be sin who knew no sin, so that in him we might become the righteousness of God. (2 Corinthians 5:21)
For we do not have a high priest who is unable to sympathize with our weaknesses, but one who in every respect has been tempted as we are, yet without sin. (Hebrews 4:15)
3. There is nothing we can add to Jesus’ finished work on our behalf.
He has no need, like those high priests, to offer sacrifices daily, first for his own sins and then for those of the people, since he did this once for all when he offered up himself. (Hebrews 7:27)
But when Christ had offered for all time a single sacrifice for sins, he sat down at the right hand of God. (Hebrews 10:12)
“So you also, when you have done all that you were commanded, say, ‘We are unworthy servants; we have only done what was our duty.’” (Luke 17:10)
4. Salvation is God’s gift to us—and so is our faith.
But the free gift is not like the trespass. For if many died through one man’s trespass, much more have the grace of God and the free gift by the grace of that one man Jesus Christ abounded for many. (Romans 5:15)
For by grace you have been saved through faith. And this is not your own doing; it is the gift of God, not a result of works, so that no one may boast. (Ephesians 2:8-9)
5. We could not keep the law perfectly because of our sin.
For all have sinned and fall short of the glory of God. (Romans 3:23)