“For it is impossible to renew to repentance those who were once enlightened, who tasted the heavenly gift, became companions with the Holy Spirit, tasted God’s good word and the powers of the coming age, and who have fallen away, because, to their own harm, they are recrucifying the Son of God and holding Him up to contempt” (Heb. 6:4-6).  

These verses from Hebrews are famously scary. But we hear these verses saying something they are not: if we fail a lot after receiving Jesus we’ve fallen away and are crucifying him again. Hebrews does speak to this type of situation, but it’s more to encourage us to trust that Jesus’s sacrifice is enough and we can approach the throne of grace to find the help we need.

In context, those “who have fallen away” are those who returned to Judaism.  They rejected God speaking in His Son (1:3); they returned to the partial testimony of the old covenant in which God spoke at many times and in various ways through angels, prophets, the law of Moses, and the levitical priesthood.  The writer of Hebrews says that those who fall away “are re-crucifying the Son of God and holding Him up to contempt” (Heb. 6:6).  Jews who didn’t accept Jesus had no option but to crucify Him because the law demands that blasphemers and false prophets be executed.  If someone returned to Judaism, they were in agreement with the crucifixion of Jesus and the public contempt He was subjected to.  In their hearts, they were crucifying Him again.

The danger isn’t exactly the same for believers today.  Most Christians are not converts from Judaism.  But we can lack clarity in our hearts about the place of the old covenant.  

Hebrews presents the Son as God’s full message; His offering completely purified from sin; the Son destroyed the devil and the power of death; He is our high priest and brings a new priesthood.  In short, the totality of God’s activity is in the Son; the totality of our relationship with God is in the Son.  The writer of Hebrews is anticipating the discussion of covenants coming in chapters 8-10.  The Son is our covenant.  There is no longer any other.

But we can lack clarity about the totality of the Son.  In ways, we can try relating to God through both covenants.  Instead of seeing the old covenant as speaking of the Son and fulfilled in the Son, we can let the old covenant remain in effect with Jesus merely being a new figurehead.  Before it was Moses, now it is Christ.

But Christ did not just take over management of the same ineffectual system.  Jesus became an entirely new approach to God.  Instead of giving commandments for us to obey, the Son is the commandment written on our hearts (Heb. 8:10).  Instead of repeated sacrifice to cover sins, the Son perfects us forever by one offering (Heb. 10:14).  Instead of entering a man-made sanctuary, the Son entered heaven itself (Heb. 9:24).

To the extent we lack clarity about these things, we take on the burden of trying to please and relate to God.  In a word, we take on the burden of trying to be the Son ourselves.  To mix in elements of the old covenant is to be drawn away from the Son by the allure of our own religious accomplishments.  It means emptying the law of its divine purpose: the law wasn’t meant to make us righteous as we kept it.  It was meant to lead us to the Son who is the substance of it.