The qualifications for pastor are simple: Above reproach.
Though 1 Timothy 3:2 and Titus 1:6 use different words, the meaning is the same. as evidenced both by the lexical data and the context. This qualification is followed by a list of representative characteristics of what it means to be above reproach. I take these lists to be representative because first, they are different, and second, there are many aspects of being above reproach that are not found in these lists but are found elsewhere in the NT and in the application of the NT teaching.
The question is often asked, What does it mean to be above reproach? I answer that question simply by saying, It means to be a model of what it means to follow Christ with no evident areas of legitimate criticism that are unaddressed. He has no public marks of shame or life dominating sins, and his private life is under control growing in Christlikeness. (Feel free to help clarify or add to that addition in the comments).
The pastor is to be a model of what it means to be a growing Christian. He is not perfect, nor will he be this side of the coffin, at which point he will be disqualified from pastoring anyway. He is to be maturing in every aspect of Christian growth. He should be a man that parents can point their sons to and say, "Grow up to be like him," and point their daughters to and say, "Grow and marry a man like him."
This qualification of "above reproach" refers to the current state of a man's life. It does not require necessarily that he never have committed any of the sins in the list, or even that he never committed them habitually. It means that his current state of life is blameless to the point that his past sinful habits have been swallowed up in and virtually forgotten in light of his present inner and outer godliness.
Sometimes people ask "What if ..." questions about the qualifications. What is interesting is that no one seems to ask, "If a man has ever lost his temper, can he still pastor?" Or "What if he was constantly angry before he got saved but changed after he got saved; can he be a pastor?" (Do you see where I am going with this yet?)
But you often see people ask those very questions about divorce. "If a man has ever been divorced or committed adultery, can he ever pastor again?" Or "If a man was divorced or committed adultery before he got saved, can he still be qualified to pastor?" It is as if many elevate one characteristic of "above reproach," namely "one woman man" in its various interpretations, above all others. Yet it seems to read something into the text that Paul does not have in mind. There is not exegetical reason why "one woman man" is on a different level than temperate, respectable, hospitable, or any other qualification.
Furthermore, I think such questions are missing the point. It implies (unintentionally I am sure) that grace for unbelievers in marital failure is somehow different than grace for believers who have committed marital failure. I do not believe that someone who believes that a post-salvation divorce disqualifies while a pre-salvation divorce does not intends to distinguish these kinds of grace. But I do not see how they avoid it.
The argument would be essentially that a saved person would know better and would be sinning directly against what they know and believe to be true. But the truth is that an unsaved person, because of common grace (the law written on their hearts; the image of God in man) knows better. There is virtually no segment of society that thinks adultery is okay. If they thought it was okay, they would not be hiding it. So the fact is that both saved and unsaved through instinct and revelation know that adultery is wrong. So that seems a hard argument for me to buy.
There are some who believe that divorce or marital failure permanently disqualify a man from ministry. I can understand that view. I do not necessarily agree, though I think it would be very hard for a divorced man to regain a state of blamelessness. It might take thirty, or thirty-five, or fifty years to regain blamelessness. And in fact, he may never do it. But his disqualification is, in my view, not the marital failure but the lack of being above reproach.
When Paul wrote "above reproach," I do not think he had in mind "Before he was saved" or "after he was saved." I think he meant, "What is his life and testimony?"
Here's the point: "Above reproach" is about the current state of a man's life. Do people look at him and say, "There's a guy who knows God and can preach the word. There is nothing in his life that screams out against his God and his God's word."
I think we should take all the qualifications for pastor seriously. Not just the one about being a one-woman man.
What God demands of a pastor is what God expects of everyone. The reason he demands it of a pastor is because the pastor is a model of the Word that he preaches. If he is to handle the Word rightly, and he must, he must back it up with his life showing people how to live it.
Therefore, he must be above reproach.