Mat 27:41 So also the chief priests, with the scribes and elders, mocked him, saying, Mat 27:42 "He saved others; he cannot save himself. He is the King of Israel; let him come down now from the cross, and we will believe in him.
It is funny how even Christians can think a lot like those who stood around and mocked Christ as he was being crucified. They assume that believing in Christ is as simple as being convinced that he was who he said he was. But no one has ever been saved by being convinced that there is a God or that Jesus died for them or that they are sinners, etc. All are saved by the proclamation of the gospel and the work of the Holy Spirit to give them a heart to believe, repent and trust in Christ.
If Jesus had come down off the cross in response to their mocking I think we can assume that they would have had a change of mind, but not a change of heart. Now they had seen Jesus raise Lazarus from the dead and most if not all did not even have a change of mind, so it is no guarantee. But it is very probable that some there would have been convinced that he was indeed the Messiah. The problem is that they still would have remained lost in their sins. The same could be said if God appeared in Heaven and said, “Here I Am!”. This is what many say must happen for them to be convinced. Without doubt all who saw that would be convinced that God exists; so what?
The one thing missing from convincing someone that there is a God is a changed heart. They might believe in him and they might fear him; many in false religions do right now. But their hearts have not been changed to love God above all else and to trust in him alone for their needed righteousness. They might try to obey him either in fear or in some sort of self-righteous attempt to please him and earn his favor but without love all obedience is so much religious activity as 1 Cor. 13 tells us.
True righteousness is to love the Lord so much that everything we do is so that he might receive all the glory. Obviously we are a long way from that and will only be fully righteous in glory. But this also helps us understand the righteousness of Jesus that we need in order to be justified before God.
Jesus is completely unlike any religious leader that has ever been. They can only point to some way of salvation. But Jesus never pointed to anything other than himself. There is no system to follow because Christ is the system although he isn’t a system but a person. And we need to understand that Jesus didn’t merely follow the Law while he was on earth as if it was a system he had to follow in order to be righteous. He didn’t get up each morning, read the Law and then make sure he obeyed it. He couldn’t help but live the Law because he perfectly loved the Father and could only do what pleased the Father. This is true holiness, not trying to obey but a perfect love that can’t help but please him in everything.
This is the holiness that we will only fully get in glory. Even though we have been given a heart to obey, we love ourselves too much to even begin to live like Jesus did. But one day we will love the Lord with a perfect love and be perfectly happy and fulfilled in delighting in God alone. This is the message of the Bible; that through Christ we can be restored to what God intended us to be.
Salvation is being given this new nature, not being convinced by strong arguments and compelling evidence that God exists. I am all for using strong arguments and evidence to show the skeptic that they are not thinking rightly, but at the end of the day the church’s commission is to preach the gospel because it alone is the way the power of God is used in the conversion of the lost. It alone is how the Holy Spirit turns a rebel into a lover of God. Even if Jesus comes off the cross, they might be convinced but they will not be converted.