“As we have said before, so now I say again, if anyone preaches any other gospel to you than what you have received, let him be accursed”
As we have said before,
The phrase “said before” refers to Paul’s previous warning about gospel counterfeits hurting his team’s visit to Galatia. This attack on false teachers was no temper tantrum. He calmly and deliberately reiterates his point.
so now I say again,
Paul says in effect, “I told you before, and now I am telling you again.” He did not and will not change his mind on this crucial doctrine.
if anyone preaches any other gospel to you
Paul addresses the actual state of affairs in the churches in Galatia.
than what you have received,
The idea of “received” is welcome. The Galatians embraced the gospel warmly when Paul’s team was in Galatia.
let him be accursed
It is not enough to reject the teaching of false teachers, but we should hold them in abhorrence.
Christians should hold in abhorrence those who impugn the cross.
Those who add works to salvation impugn the cross. The very nature of the gospel is at stake when people introduce works into salvation or sanctification. Because of this, we hold those who change the gospel in abhorrence.
“If anyone comes to you and does not bring this doctrine, do not receive him into your house nor greet him; for he who greets him shares in his evil deeds” (2 John 10-11).
In grace, the curse falls on Christ (Galatians 3:13). Under legalism, the curse falls on man.