Arguments against abortion are not religious, but about recognizing the right to life of every human person.
Arguments against abortion are often put in the context of religion faith, making it a religious issue based on what you believe about God.
However, the issue is technically not about religion at all. Abortion concerns the intentional killing of another human being, and is similar to murder, meaning that it violates a basic human right to life that is outside of religious belief.
Pope Francis has spoken about this multiple times, such as this quote from 2019.
Is it fair to eliminate a human life in order to solve a problem? The answer to which is: no. Second question: Is it fair to pay a sniper to solve a problem? No. Abortion is not a religious problem in the sense that just because I am Catholic I must not seek an abortion. It is a human problem. It is a problem of eliminating a human life. Period.
Scientific data on life inside the womb further cements this reality, proving that a human embryo is exactly that: a human.
The Sacred Congregation for the Doctrine of the Faith pointed this out back in 1974, in their Declaration on Procured Abortion.
[M]odern genetic science brings valuable confirmation. It has demonstrated that, from the first instant, there is established the program of what this living being will be: a human, this individual human with his characteristic aspects already well determined. Right from fertilization is begun the adventure of a human life, and each of its capacities requires time–a rather lengthy time–to find its place and to be in a position to act. The least that can be said is that present science, in its most evolved state, does not give any substantial support to those who defend abortion.
Abortion violates the natural right to life of every human person. This isn’t established by religion, but by our shared humanity.
If murder is wrong in our human community, than it must follow that abortion is in the same category.