Q. 1. What is a "spiritual father?"
A. 1. The term "spiritual father" is another title for a Godfather or male sponsor.
Prior to the 5th century, the Godparents were called "guarantors". By the 5th century, they were referred to as "spiritual fathers". Over time, the title of Godparent or Sponsor has changed.
The term "spiritual father" as a Godparent is no longer used. If anything, the term of "spiritual father" sounds like a title you would give to a priest who counsels someone in their spiritual life.