Eternal sin
In Catholic teaching there are six sins that blaspheme against the Holy Spirit. They are: Several passages in the Bible are frequently interpreted as referring to the unforgivable sin:
Religion and abortion
There is scholarly disagreement on how early Christians felt about abortion, and no explicit prohibition of abortion in either the "Old Testament" or "New Testament" books of the Christian Bible. Some scholars have concluded that early Christians took a nuanced stance on what is now called abortion, and that at different times, and in separate places, early Christians have taken different stances. Other scholars have concluded that early Christians considered abortion a sin at all stages; although there is disagreement over their thoughts on what type of sin it was and how grave a sin it was held to be, it was seen as at least as grave as sexual immorality. Some early Christians believed that the embryo did not have a soul from conception, and consequently, opinion was divided as to whether or not early abortion was murder or ethically equivalent to murder.