Kathy:
If we are human beings at conception, I would assume that you mean we have souls at that point. However, if "ensoulment" takes place at conception, how do you explain the fact that, by conservative estimate, about two thirds of the fertilized ova - human beings with souls according to you - do not live longer than one month. About half the fertilized ova are grossly deformed and die. Of those remaining, some fail to implant in the uterine wall and are flushed out in the next menstruel period. Others do implant and reproduce by cell division; but the cells fail to differentiate. Thus, no unmbilical chord is formed, and they too are swept away in the next menstruel period.
I read this in an issue of "Christianity Today" from the 1980s. As I said, the two-thirds number is a conservative estimate. Others place the number of fertilized ova that only live a month or less as high as 80%. This is in well-nourished, healthy women, free from either physical or emotional trauma.
Thus, to accept ensoulment and human status at conception, we must believe that God allows to exist a situation in which the majority of the human race exists only briefly in the womb. Considering the doctrine of Original Sin, these humans would have to be considered depraved, unregenerate sinners and as such consigned to eternal damnation.
Are you sure you want to assert humanity and ensoulment at conception, considering the implications outlined above?