I know most don't care, but the Catholic church stands against Capital Pinishment and Abortion. Their doctrine is to respect all life at all stages from fertization of the egg to a natural death.
It seems pretty logical to me that if cell division is taking place, then there is life. I'm sure that if NASA found a one-celled organism on Mars, which is less complex than a human zygote, they would proclaim to the World that life has been discovered.
Also, anyone who has read the Bible knows that Jesus said, do not Judge, lest you'll be Judged. Believe the Bible or not, I would not sit in judgement to execute another person. I wouldn't even do it for a family pet. God created life, and it is his to take it away at the time and place he decides. The only exception I'll make is if someone is attacking my Country, my family or me.