I work with several born-again Christians, but sadly, no Catholics. Not any who are practicing their faith, anyway. Born-agains are on fire for their faith, but they have so many misconceptions about the Catholic faith. It's like they've been poisoned against it. One fellow I worked with "found out" I was Catholic when my phone rang, and the person calling me asked about the practice of making sacrifices for Lent, and why some Catholics allow themselves, on Sundays of Lent, to have what they gave up. After the phone call, he said to me, "So you're Catholic, then?" (I knew all along he was a non-Catholic Christian by the plain cross on his lapel).
I told him I was a traditional Catholic, and later, during lunch, he pulled out a little King James bible from his jacket pocket, flipped to Matthew 23:9 "And call none your father upon earth; for one is your father, who is in heaven", and asked me what the meaning of that passage was, and why we call our priests Father. I noticed as he flipped through his Bible that he had many passages such as this one highlighted.
The next part of that passage is "Neither be ye called masters; for one is your master, Christ". The meaning, as far as I understand it, is that our Father in heaven is to be regarded higher than any father upon earth, and we are not to follow any master who would lead us away from Christ. But this doesn't mean that we can't respect our parents, spiritual fathers and teachers, because the fourth commandment expressly commands that we should.
There are also many other places in Scripture that support the Catholic use of Father for our priests. Take a look at Acts 7:2 where St. Stephen calls Jewish leaders father: Who said: Ye men, brethren, and fathers, hear. The God of glory appeared to our father Abraham, when he was in Mesopotamia, before he dwelt in Charan. And again in Acts 21:40 and 22:1, St Paul also refers to Jerusalem Jews as fathers: Men, brethren, and fathers, hear ye the account which I now give unto you.
Abraham is called the father of us all in Romans 4:16-17: Therefore is it of faith, that according to grace the promise might be firm to all the seed; not to that only which is of the law, but to that also which is of the faith of Abraham, who is the father of us all, 17 (As it is written: I have made thee a father of many nations,)
And what about 1 Corinthians 4:14-15 where St Paul calls himself 'father': For though you have countless guides in Christ, you do not have many fathers. For I became your father in Christ Jesus through the gospel. Surely this is strong evidence of why we call our priests Father. In the first epistle of St John, I John 2: 13, he says, I write unto you, fathers, because you have known him, who is from the beginning. Finally, and once again, in Philomen 1" 9-10, St Paul gives a perfect example of our tradition of calling priests father, where he says this: I, Paul, an ambassador and now a prisoner also for Christ Jesus --  I appeal to you for my child, Ones'imus, whose father I have become in my imprisonment.
I wish I had all of these references available to me that day when my co-worker was demanding to know how we dare to call our priests by the term father. At least now, I will be better armed if the subject comes up again.