Paul writes first of
“the washing of rebirth,” which is surely related to the divine regeneration of
the human heart through faith in Christ alluded to in John 3:3–8. Water baptism
is a recognition of and catalyst for this spiritual but real transformation. It
is difficult, and unnecessary, to make a radical separation between the two.
(Robert W. Yarbrough, The Letters to Timothy and Titus [Pillar New
Testament Commentary; Grand Rapids, Mich.: Eerdmans, 2018], 546)