Let's assume for now that God is not involved. I know, the conservatives can't and won't do that, so label me a heretic and move on to the next thread. But let's, the rest of us, look again at this passage in purely temporal terms. Take God and any intervention out of it; let's pretend it was added later by the writer. What are we left with?
What is apparent is that Joseph has a compassion and a tolerance that goes far beyond his faith. Whether Mary was pregnant before they were betrothed or after, Joseph has a lot of legal options available to him that, to be kind and diplomatic, can put Mary in a bad way. He would have nothing to fear or regret, because by law and faith he would have done the right thing. The dream sequence of the passage, however, gives me the suspicion that Mary becomes pregnant after she is betrothed to Joseph. There is no evidence one way or the other, but I fail to see why Joseph would need reassurance from a dream if he was not engaged already to Mary.
So, again, God is taken out of this - you're betrothed to a young lady that managed to get herself pregnant, and it isn't yours. Now here is where I reject the immaculate conception idea; I think it's demeaning to women, it invites the notion of an interaction between god and mortal much along the lines of Zeus, and if God is all-powerful then God doesn't need to break matrimonial laws and procreate this way. I find the whole sequence entirely distasteful. But, if I take God out of that, then I have a story of a man who's fiancee has fooled around on him and shows a breathtaking compassion for his bride. Sure, he thought about dumping her - who wouldn't? But he doesn't. He sticks with her and with her unborn child, marries her, and still sticks with her. I read this and I find it hardly believable. I also read it and am not surprised that the compassion and good works of this man rub off on Jesus and are revealed at every point of Jesus' ministry. Joseph was not Jesus' father, but the life and ministry of Jesus surely would never have culminated the way it did without the influence of Joseph. Yes, you can be God on earth but if you're raised by an idiot then you will fall victim to your environment. Jesus learns no small amount of his ministry from his stepfather.
Then, there is the curious event of the three wise men. They follow a star and come upon a baby, and offer it gifts. I read this and it has a hint of truth to it. Let's face it - religious types do nutty things for nutty reasons. Is it really outside the realm of belief to think that three magi from the east followed signs and came upon Jesus, giving him gifts? Doesn't the search for a new Lama happen similarly, with elders/wise men following signs and selecting a new leader based solely on the signs? I read this and think "Perhaps...." and then we come to the gifts themselves. Gold, Frankincense, and Myrrh. In all my life I was never offered an explanation of why these were important gifts. Gold, yes - but frankincense? Myrrh? I was told that frankincense was used in perfumes and myrrh was dhfjdfiweuyfaaksd. Yeah, made no sense to me. Then I became a luthier.
Joseph is described as a carpenter. That's not an accurate word for today, especially for North Americans, and I will not presume to speak for other parts of the world, but here a carpenter is a house builder. That's not what Joseph was. Joseph was a woodworker. When you think of Joseph in those terms, then frankincense and myrrh make all the sense in the world. Why? Those are resins used in finishes - in varnish. I have some of both in my shop. What the wise men gave to Mary and Joseph was the means to get out of their poverty; gold for the short term, and some gum resins so that Joseph could put a finish on his work and sell it at a much better price. So much better that Joseph becomes something of a middle class merchant from his trade.
Even if you take the supernatural out of this story, there are fascinating components, and it is possible to find some plausibility in the story. It is possible to find a spiritual depth if that is what you're looking for, something that you can apply to your life if that is what you're looking for, or maybe just a great made-up story if that is what you're looking for. Your choice.
Merry Christmas to you if you observe Christmas. If you do not, then best wishes to you this holiday season and may your next year be better for you than the last.