Today's Gospel gets pulled out a lot in arguments against Catholicism. Jesus clearly says, "Call no one on earth your Father," and here we Catholics have been flagrantly ignoring this divine injunction for centuries! And not just Roman Catholics, but even the old hermits in the deserts of Egypt with their "Abba Poemen" and "Abba Dorotheus" and so on.
Sad to say, some people have actually had their faith shaken over this.
But even Paul claimed (for himself!) the title "Father" when writing to the Corinthians. And why? Because "I begot you in Christ Jesus through the Gospel."
So whether it is Paul or Father so-and-so at the local parish, the "fatherhood" in question is itself evangelical. The Gospel shows that this fathering can't just be a matter of empty words: that would put the focus on the speaker and not on the new life being called forth. That's the problem Jesus had with the Pharisees of his day (and ours?).
Good thing it's Lent!