Yet you would disregard as irrelevant one of the powerful examples of God’s love, mercy and grace, given to one who did not deserve it. An act so important, that God who inspired the word, made sure that as one of Jesus’ last acts on this earth was recorded for all believers to see.
Irrelevant? Not at all. But its relevance does not include using it as an example that baptism is not for the remission of sins today.
God told Noah to build an ark of gopher wood. That has relevance. But its relevance doesn’t mean that we should build one as well. There were various sacrificies offered under the Old Covenant. These are relevant today, but their relevance does include our following that example. We are under the New Covenant.