There is a lot to disagree with in your statement.
First, you use "murder" incorrectly. Abortion, in the US, is legal, and therefore not murder. Murder is defined as an illegal killing. That is why when someone is given the death penalty, they are said to be killed, not murdered. We say soldiers kill the enemy, not murder the enemy. By using "murder" you are adopting the conflation that anti-abortion activists have been (apparently) successful in promoting.
Second, nobody doubts that a zygote is alive. Nearly every cell in your body is alive (barring hair, nails, upper layers of skin, recently recycled cells), including sperm and eggs. When an egg and a sperm fuse, the result is also alive. The question is whether the rights of the zygote->blastula->fetus->baby trump the rights of the woman who is carrying it.
Obviously, by the time it becomes a baby, the baby's rights trump the desires of the woman carrying it, in general -- everybody agrees on that. Some people conceive (pun not intended) of the fertilized egg as being fully human, something God ordained and which is the vessel for a soul which has been waiting for that very zygote, and by aborting it, one is subverting God's will and destroying the intended future destiny of that soul.
Others don't share that belief. There is certainly no bright line dividing when that fetus is developed enough that its rights are superior to that of its mother, and deciding where to place that light should not be taken lightly and will cause discomfort. But we deal with such things all the time. It is legal to drive 45 MPH on the street near my house, but not 46. Yes it is somewhat arbitrary but not unreasonable either. That we have to make an uneasy boundary somewhere on the continuum isn't reason to declare that the speed limit should be zero, or that there should be no speed limit at all.
It should also be noted that at the time Roe v Wade was decided, Protestants and even evangelical Protestants by and large were not bothered by the decision. Catholics were, of course. It wasn't until the rise of the Moral Majority that the issue became objectionable to so many religious groups.