Why Do We Say, "Father, Son, Holy Spirit?"

What might the sequence mean and is it important?

A shoutout to Madison Pierce for her excellent contribution, 'Trinity without Taxis? A Reconsideration of 1 Corinthians 11' in which she states that the "early Christians recognized an ostensible hierarchy in the Father–Son (later also – Spirit) relationship that they sought to reconcile with their understanding of the unity within the Godhead. What they initially developed was an understanding of taxis (Greek and Latin for double 'order' or double 'ordering') in which the three are distinguished by their number and sequence but not ranked, so to speak" (p 46).

Do read her work there to find a keen analysis of alternative readings for kephalē (the Greek term translated 'head' in 1 Cor 11:3) and the solid and faithful conclusion she opts for.