Here are a few reasons why:
God made Eve from Adam, they were joined together to be one flesh. (Genesis 2:22-24)
22 Then the LORD God made a woman from the rib [j] he had taken out of the man, and he brought her to the man.
23 The man said,
"This is now bone of my bones
and flesh of my flesh;
she shall be called 'woman,'
for she was taken out of man."
24 For this reason a man will leave his father and mother and be united to his wife, and they will become one flesh.(NIV)
Now if my wife and I were to have separate last names that certainly does not say one flesh. That says 2 individuals. At weddings you light the 3rd candle and blow out the individual candles signifying bride and groom as individuals. Some traditions have bride and groom pouring 2 separate vases into a larger vase to signify the new union. Then there's the 3 strand rope intertwined to signify the new relationship between husband, wife, and God. No matter what your custom is these all signify the end of the individual and the beginning of the new union with God. So to me, not changing your name signifies a person is not totally committed.
Furthermore, name changes in the Bible mark the beginning of new paths in life just as marriage does. For example when Jesus invited Levi to get down with the Home team, he became Matthew. When Saul got down with the Home team he became Paul. When God told Abram his plans for him to become father of many nations he changed his name to Abraham. The same thing happened with his wife Sarai, she became Sarah the mother of many nations. Of course in Biblical times they didn't have last names. Most people were Such and so from some place (ie Jesus of Nazareth,). Or Such and So son of SuchandSo like James the son of Zebedee, which is not the same James as James son of Alphaeus (who may or not be Jesus' brother depending on who you ask). But nonetheless name changes mark new beginnings.
Paul talks about man and wife being equally yoked. Which means having very similar spiritual views and beliefs about religious doctrines. Paul also talks about husband and wife submitting to each other. In case you missed it, check out my post on submission . I plan on having a Christian marriage because I'm a Christian and my faith is very important to me. But let's exam this from a secular lens. After all, what good is faith if it can't be used to be a shining light to a dying world?
When a man wants to marry a woman, what's the first thing he must do before he proposes? Ask for permission from her parents/father. Now in this day and age with many of our Black homes being broken homes, often there isn't a father present to ask. But nonetheless any respectful man should ask a parent for permission to marry their daughter. Well why is this so important? Becuase you're taking their daughter away from them! She's becoming your wife and you guys are starting your own family. That's not to say that she no longer has ties to her family but that her primary family has changed. At the wedding, why do you think somebody "gives the bride away". Because she's leaving her family to join another family. The man does the same thing, when he's married he's creating his own branch on the family tree. If you subscribe to the idea of the man as the head of household, as I do, it makes perfect sense that the family should have the man's last name. But here's the problem with that, not enough people believe the man is the head of the household.
There are many reasons I believe this ideology has died. First there's the increase of women in the labor market and the feminist movements of the late 60s and 70s where women were asserting their independence from the traditional wife roles that society had burdened them with. Statistically, this also lead to an increase in divorces and a decline in traditional family structure. I'm not saying feminism is to blame, in fact, I'd argue that men are to blame. If we treated our women right, loved them like we should and fulfilled our roles as head of household, there would probably be a lot less divorce. Within our Black community, many people are growing up in single parent, female-headed households. That's all that a a majority of my generation knows. I grew up in a similar situation (well most of the time i had a two female-headed household but it was a female headed household nonetheless). I'm not saying a female headed household is a bad thing but I do realize that it'd be hard to convince a lot of women to let a man be the head of the household and to submit to their husband if they grew up with a woman running the household.
I've heard many arguments for women not changing their name, some having more weight than others. I've heard things as silly as "I decided when i was 13 I wasn't changing my name, so I don't care if I marry Jesus, I'm not changing my name to Christ" to "My father doesn't have any sons and I don't want my family name to die out" If the woman of my dreams was concerned about her family name dying out, she could use it as her middle name and I'd be willing to give our children 2 middle names, one of which would be her last name. But, I'm not cool with the hyphenating. Because my name isn't Fuller-Knowles/Dash/insertsomeotherfinewoman'slastnamehere. But if she was the woman of my dreams which Lord willing she will be I'd be willing to compromise if it was REALLY important to her. But in all honesty, I'm not even sure we would get to the marriage convo if she wasn't down to change her last name. I'm not saying it's a red flag, but it's certainly a yellow light! I may be labeled a sexist, chauvinist, or "insert some other derogatory term for a male here". But these are my beliefs. You don't like it? That's fine,