Part 1 is available here.
TWH: The Gospels do not present Jesus as being married or as having ever been married. Since the Gospels focus on the ministry of Jesus, a period of roughly three years, and pay special attention to the last week of that ministry, some have speculated that Jesus could have been married at some point in his life, before or after the beginning of his public ministry, and possibly widowed prior said period. One thing that I love about this question is it is one of the major points of Jesus' life that scholars are actually in agreement with one another, and that includes scholars all across the theological spectrum.
Did you know that a Mormon once suggested that Jesus was married? He proposed in 1857 that Jesus had a polygamous relationship with the two Mary's, Martha, and others. In fact, he even told a congregation, to whom this message was delivered, that the wedding at Cana recorded in John 2 was one of Jesus' weddings. Now you can guess why a Mormon might be interested in a married and polygamous type of Jesus. I point it out because (1) it's interesting historically speaking, (2) to show that this isn't something associated exclusively with the antireligious (though I believe Mormonism to be a cult), and (3) it shows this isn't really a new phenomenon (i.e., we can't tie it to the penning of The Da Vinci Code in 2003).
There is nothing, though, in the historical Gospels (Matthew, Luke, Mark, and John) that indicates that Jesus was married or ever had been. Let me just offer a few comments.
First, Jesus' support and affirmation for traditional marriage (e.g., Matt. 5:32; 19:9-10; 22:23ff.) is not equal to having been married. In other words, he did not have to be married in order to hold such convictions.
Second, we have to be very careful when we say that there were cultural obligations in the first century that were in actuality nothing more than cultural norms. Socio-cultural studies of any century of human history are important and enlightening for interested parties, but socio-cultural studies should be viewed as anything other than black-and-white. When we see things like "people in the first century were obligated to get married," is that really accurate? I don't think so. Most people get married. That's normal. And there might have been some serious questions raised if someone didn't get married in a culture where it was normal. But we can't say that because something was normal that all things fit into that mold. We can find many reasons to explain why Jesus would not have been married (e.g,. the death of Joseph and the need to care for his mother, brothers, and sisters until the beginning of his ministry, at which point another brother would have become of age to support the family).
Third, the silence of the New Testament cannot be considered real evidence that Jesus was married. It's true that direct reference to the civil status of most individuals is usually assumed, but that is not a strong basis for concluding or even supporting that Jesus was married. For example, we have evidence of the marital relationship of prominent characters in the Gospels and the rest of the New Testament corpus. Think about Peter. We know that he was married from the Gospel according to John. Paul even mentions that more than one of the apostles were married and were in the habit of bringing their wives along with them on their missionary travels. Peter is definitely one of them. Paul, on the other hand, is not married. For someone that was so committed to his Jewish faith and culture, he did not marry. If Paul, why not Jesus? What do people who argue in favor of Jesus' wedded civil status do with the case of Paul? Are there two exceptions to the socio-cultural obligations of first-century Judaism? It appears so. And there are more, many more, just as Antonio pointed out in Part 1. Don't forget the Essenes and others. We have to be careful with the argument from the silence of the New Testament. The Gospels are focused on Jesus' ministry in general and in particular the last week of that ministry. Still, it seems inconceivable that these records could have avoided talking about Jesus and a wife/family if he actually had one. Truth is, they would have.
Fourth, the silence of Paul when it comes to singleness is not real evidence in favor of Jesus being married. It's true that Jesus is Paul's go-to example (and he should be for all of us). Nevertheless, Paul does not use Jesus exclusively, and he doesn't use Jesus' example everywhere he could. Think about this for a second. In Paul's view, Jesus is not single. He is betrothed to the bride, which Paul tells us is the Church (Ephesians 5). That would explain why Paul doesn't reference Jesus' singleness when he discusses that topic. For Paul, Jesus' betrothal extends to a point even before the cross. In fact, the cross is for this bride.
There's lots to think about here. Jesus wasn't married if you're asking me. And not being married, we can also conclude that he did not have any children.