Baptism is a dual-aspect activity. Certainly, it is a blessing for those who receive it. It is a sign and seal of the promise of the Holy Spirit (cf. Romans 4:11).Though we often think of the baptism as an exclusively “blessing” phenomenon, there is a flip-side: the judgment aspect. Baptism is also a judgment ordeal.
In Luke 3:16, John helps explain this other aspect.
John answered them all, saying, “I baptize you with water, but he who is mightier than I is coming, the strap of whose sandals I am not worthy to untie. He will baptize you with the Holy Spirit and with fire.
ἀπεκρίνατο λέγων πᾶσιν ὁ Ἰωάννης· ἐγὼ μὲν ὕδατι βαπτίζω ὑμᾶς· ἔρχεται δὲ ὁ ἰσχυρότερός μου, οὗ οὐκ εἰμὶ ἱκανὸς λῦσαι τὸν ἱμάντα τῶν ὑποδημάτων αὐτοῦ· αὐτὸς ὑμᾶς βαπτίσει ἐν πνεύματι ἁγίῳ καὶ πυρ
Immediately following this statement comes a description of the Messiah’s function as judge.
His winnowing fork is in his hand, to clear his threshing floor and to gather the wheat into his barn, but the chaff he will burn with unquenchable fire.
οὗ τὸ πτύον ἐν τῇ χειρὶ αὐτοῦ διακαθᾶραι τὴν ἅλωνα αὐτοῦ καὶ συναγαγεῖν τὸν σῖτον εἰς τὴν ἀποθήκην αὐτοῦ, τὸ δὲ ἄχυρον κατακαύσει πυρὶ ἀσβέστῳ
This judgment aspect of baptism is also apparent in 1 Corinthians 10:1-2 when Paul describes Israel being baptized by passing through the Red Sea. Likewise, Noah and his family were baptized in a sense as they passed through the judgment of the flood (cf 2 Pet 2). So as we recognize the dual aspect to baptism, we can see how the same sign can be a blessing to those called (e.g. Israel in the Red Sea) and a judgment for others (the Egyptians). Being united to Christ, we are baptized into his death (Rom 6:3) we no longer live but Christ lives in us and we live lives of faith in him (Gal 2:20). Christ has undergone the judgment ordeal for us and we live lives free from the power of sin.