Throughout the Bible, there are many instances where simple people have been used by God to do great things. Think of Joseph, Moses, Samuel, David, Gideon and so many more! Were they 'qualified' to do the work God chose them to do? No way! But God accomplished His purpose through these people.
Paul's background plays a huge role in how God used Paul. It was Paul's faithfulness to the law that gave Paul credibility with the Jews. It was Paul's zealousness for the law that caused him to be such a powerful opponent of the early church. It is Paul's moral integrity that gives him credibility on marital matters, even though he was never married. So, yes, Paul's background matters and if were divorced, God couldn't have used him in the same way.
The other poster also wants to believe Jesus was raised in a single-parent home, as if that would somehow justify women who become single mothers through fornication. Mary wasn't guilty of fornication. And, Jesus wasn't raised in a single-family home. We know from the Bible that Joseph was still around when Jesus was twelve, the cusp of adulthood. And, we have no evidence that Joseph had died until Jesus was about 30. And, that would be death, not divorce.