As pro-life Christians we can co-labor with pro-life Catholics to promote life and accomplish certain political goals (i.e. repealing Roe v. Wade, fighting pro-abortion legislation, campaigning for pro-life candidates, etc.), but we have to be careful not to enter into spiritual enterprise with them for the simple fact that Roman Catholicism is an apostate form of Christianity. The Roman Catholic Church holds to a different gospel and actually forbids anyone from believing in the biblical gospel. The RCC actually goes as far to pronounce a curse on them (Council of Trent). The Roman Catholic Church's false gospel has damned many souls to hell and continues to do so even today!
As passionate as we are about saving babies, we cannot compromise the gospel. Our primary mission and command from the Lord Jesus Christ is to preach the gospel and make disciples. We don't set aside this command to partner with pro-life Catholics who are opposed to the biblical gospel for the sake of protecting the life of the unborn. As important as protecting the life of innocent and helpless babies is, the gospel must be first and foremost. If it is not, then we are off mission and we need to get back on mission! (See: Should a Christian be involved in the ecumenical movement?)
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Many Catholics are pro-life, but that does not necessarily make them a Christian (anymore than walking into your car garage will make you a car). We have to be careful not to judge people only by their moral fruits but also by their doctrinal fruit. Unless one has been regenerated by the Holy Spirit (by faith in Christ alone, by grace and not of works Eph.2:8-9), then even his best works are seen as filthy rags (used menstrual rags) or what the Apostle Paul referred to as rubbish (dung) by God. A person who has truly been born of God rejects false teaching and eventually will be left with no choice but to leave the false religion of Rome and all her abominable doctrines or else this is evidence that they are not a Christian.
If one adheres to the teachings of the Catholic church then he is not a Christian, because the Catholic church teaches that you are not saved by faith alone, but have to keep the sacraments in order to be saved (Catechism pages 1815, 980, and 1129). Christian apologist and former Catholic Phil Fernandes PhD. says that he would venture to say that less than 5% of Roman Catholics actually have saving faith in Jesus Christ. It's important to note that if a Catholic does come to a saving faith in Jesus Christ, then by definition he is no longer Catholic. Because to be Catholic is to identify with the Catholic church and it's teachings which are antithetical to the Bible and contrary to the way of salvation that Jesus Himself and the Apostles proclaimed.
The Catholic church maintains that one must keep the seven sacraments (Catechism page 1210): baptism, confirmation, eucharist, penance, extreme unction, holy orders, matrimony (five of which it created; the Bible only mentions two) in order for salvation (Catechism pages 1127-1129). But even then the Catholic church states that you cannot be sure. They even go as far to declare a curse against someone who would announce that he is certain of his salvation and that he knows he is going to heaven when he dies (Council of Trent). The Catholic church teaches that one has to die in a 'state of grace' in order to go to heaven and avoid purgatory. Catholics need to have a priest perform what is commonly referred to as the 'last rites' and make one good last confession in order that the priest may forgive one's sins and assure that one dies in a state of grace, but even the Catholic church says that one cannot be sure of one's state of grace (Catechism page 2005), as one can only hope for the grace of final perseverance (Catechism page 2016).
The following is excerpted from Steve Camp's article titled "WORLDLY SAINTS...being salt and light in a pagan society":
[The apostle] Paul says..."But when the kindness of God our Savior and His love for mankind appeared, He saved us, not on the basis of deeds which we have done in righteousness, but according to His mercy, by the washing of regeneration and renewing by the Holy Spirit, whom He poured out upon us richly through Jesus Christ our Savior, so that being justified by His grace we would be made heirs according to the hope of eternal life." This is one of the richest passages of our great salvation we have in Christ Jesus our Lord found anywhere in all of Scripture. Notice the banner of our salvation surmised in three key words: He saved us… This again is cause for great humility. We couldn't save ourselves not [even] on the basis of deeds which we have done in righteousness. Our best works, our best religious works are filthy rags (Isaiah 64:6) sufficient only to damn us to hell, but save us? Never! This is the nail in the coffin of Romanism-of any good works/human achievement system of obtaining favor with God. All our good works, even religious ones, are nothing but rubbish, human excrement compared to knowing Christ Jesus as Lord of our lives by grace through faith alone (cp, Phil. 3:1-8). We were only saved according to His mercy (not our works); by the washing and renewing of the Holy Spirit (not by our merits plus grace or our works plus faith); through Jesus Christ our Savior (not through a surrogate Christ in the Roman Church; or Mary; or Papal infallibility); justified by His grace (not through infused righteousness of works, but through the imputed righteousness of Christ alone) made heirs according to the hope of eternal life (not through the suffering in purgatory to be purged of our sins and then maybe one day will be made good enough to enter glory). We have hope beloved, eternal hope, in the Lord alone! -- Steve Camp
(But When Ye Pray, Use Not Vain Repetitions, As the Heathen Do)