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.
ἀπεκÏίνατο λέγων πᾶσιν ὠἸωάννης· á¼Î³á½¼ μὲν ὕδατι βαπτίζω ὑμᾶς· á¼”Ïχεται δὲ ὠἰσχυÏότεÏός μου, οὗ οá½Îº εἰμὶ ἱκανὸς λῦσαι τὸν ἱμάντα τῶν ὑποδημάτων αá½Ï„οῦ· αá½Ï„ὸς ὑμᾶς βαπτίσει á¼Î½ πνεύματι á¼Î³á½·á¿³ καὶ πυÏ
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 á¼Î½ τῇ χειÏá½¶ αá½Ï„οῦ διακαθᾶÏαι τὴν ἅλωνα αá½Ï„οῦ καὶ συναγαγεῖν τὸν σῖτον εἰς τὴν ἀποθήκην αá½Ï„οῦ, τὸ δὲ ἄχυÏον κατακαύσει πυÏá½¶ 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.

I appeal to you, brothers, to watch out for those who cause divisions and create obstacles contrary to the doctrine that you have been taught; avoid them. For such persons do not serve our Lord Christ, but their own appetites, and by smooth talk and flattery they deceive the hearts of the naïve. (Romans 16:17-18)