I like the organization Priests for Life. I has a good, sound, and balanced pro-life approach. Let me start you off with a couple of quotes. The first one is from Scriptures; the second one is from the Church Fathers (courtesy of the website of Priests for Life).
“Come now, you rich, weep and howl for your miseries that are coming upon you! Your riches are corrupted, and your garments are moth-eaten. Your gold and silver are corroded, and their corrosion will be a witness against you and will eat your flesh like fire. You have heaped up treasure in the last days. Indeed the wages of the laborers who mowed your fields, which you kept back by fraud, cry out; and the cries of the reapers have reached the ears of the Lord of Sabaoth. You have lived on the earth in pleasure and luxury; you have fattened your hearts as in a day of slaughter. You have condemned, you have murdered the just; he does not resist you.” – James, chapter 5
Compare the quote above to the quote below:
“Why sow where the ground makes it its care to destroy the fruit? where there are many efforts at abortion? where there is murder before the birth? for even the harlot thou dost not let continue a mere harlot, but makest her a murderer also. You see how drunkenness leads to whoredom, whoredom to adultery, adultery to murder; or rather something even worse than murder. For I have no name to give it, since it does not take off the thing born, but prevents its being born. Why then dost thou abuse the gift of God, and fight with His laws, and follow after what is a curse as if a blessing, and make the chamber of procreation a chamber for murder, and arm the woman that was given for childbearing unto slaughter?” – John Chrysostom
What is common to both quotes is the concept of “murder.” In fact the word is found in both quotes. These two quotes show how strongly the Church is pro-life. The website of Priests for Life has some additional good quotes from Early Church documents, which I would recommend looking up. Needless to say, most of the quotes have to do with the subject of abortion, as one might expect. But, they are conscious of their responsibility to fairly represent the views of the Roman Catholic Church. So, they have also made their stance clear on other subjects. For instance:
“Priests for Life would like to strongly echo the Holy Father’s call for the abolition of the death penalty. Human problems call for humane solutions. Death, whether of an unborn child or of a convicted criminal, does not bring us closer to a civilization of love, but rather feeds the mistaken and dangerous notion that killing is a solution to our problems.”
Notice how abortion and capital punishment are cited together as being both pro-life issues. If you will look through their website, they are also concerned about social issues, such as poverty, etc. Priests for Life hold what they call a “Consistent Ethic of Life.” They explain this in the following way:
“Some object to the idea of the consistent ethic because they interpret “consistency” to mean “of equal importance or urgency.” That is not what it means. What links the many issues of human life is that such life is sacred: it comes from God, it belongs to God, it returns to God. All human beings have equal dignity, and nobody may ever directly destroy the innocent. These principles apply whether we are talking about abortion, capital punishment, war, poverty, drug abuse, street violence, or any other of the multitude of problems we face in society.
But that does not mean that these issues are morally equivalent. Each issue, along with the overall principles which we have already stated, has its own particular principles and moral considerations which need to be brought into the discussions whenever one treats of that particular issue. These particularities could conceivably result in divergent opinions about what specific policies should be implemented, while at the same time those who disagree acknowledge the same essential principles.
Nor do all of these issues constitute an emergency of equal gravity and urgency. Some do more damage and claim more victims than others.”
Notice that they have a good and clear definition of pro-life, but also have a good grasp of priorities and why certain issues have to go to the fore. Best of all, they accurately reflect the social teachings of the Roman Catholic Church. In most of their stances, they also reflect the stances of the Orthodox jurisdictions. [Note that the Orthodox do not fully agree with the Roman Catholic position on birth control.] They do not take a particular political stance nor assume that you must vote for a particular party.
So, if you want an anti-abortion organization to support that maintains balances, you might do well to look at this one.