The Gospel is brought to us from God himself. This means that it condescended down from heaven and came down to us. It came just as the Word itself came down from heaven: It was made flesh and dwelt among us. And because the Gospel has come down to us from heaven we cannot expect to look up at it from this world and expect to be able to peer into its truths and correctly understand it.
When the Sadducees presented Jesus with their question they also presented to Jesus how they viewed the Scriptures. From a purely worldly perspective, their question does make a certain kind of sense. If unions on earth carry into heaven then the problem they presented Jesus would indeed need to be reconciled.
But the heavenly is never subservient to the earthly and this is a basic truth these teachers should have been intimately familiar with when asking their question. The Law states that when a man or woman dies the surviving spouse is free to marry again, thus making marriage an earthly institution. The resurrection from the dead is littered through the Old Testament and so their denial of this basic truth only added to their embarrassment too.
True faith never looks with natural, earthly eyes, but heavenly ones. If we see the Gopsel rightly, we see with new eyes given to us by God himself and with corrective vision that slowly grows more powerful by the hand of the Holy Spirit within. Jesus’ rebuke to the religious elites is a rebuke to us as well. God’s Word cannot be held hostage by the world’s viewpoint and demands. A message that transcends the world’s demands also demands to be seen as it truly is, not what we think it ought to be.