That's a very naive statement, since the theologies of the evangelical and liturgical churches have absolutely nothing in common (except a vocabulary that means something completely different to each group). Their doctrines are completely contradictory to each other. They can't all be true. To pretend that Roman Catholics, Eastern Orthodox, Oriental Orthodox, Nestorians, high church Anglicans, and low church Fundamentalist Protestants all share the same religion is simply nonsense on the face of it.
To say otherwise is to simply be engaging in ecumania.
The same can be said for any of the major world religions.
Put an ultra-orthodox Hasidic Jewish rabbi from Israel in the same room with a female lesbian reform Jewish rabbi from New York City and let me know how much common ground they can find theologically, though both will be seen as "Jewish Rabbis" to the general public.
Get a follower of Tolu-e-Islam (which rejects all hadiths) in the same room with the Ayatollah of Iran and see much common ground they can agree on. Bring in some radical black activist from the "Nation of Islam" (he will undoubtedly self-identify as a "Muslim" in public) in good measure and see how much he can agree with the other two.
Have a devout follower of Lingayatism Hinudism (they are an extremist monotheistic Shiva sect that believes Shiva alone is the one true God) meet up with a Hare Krishna (International Society for Krishna Consciousness) from California. See if they agree on anything. Both will claim to be Hindus.
“That’s a very naive statement, since the theologies of the evangelical and liturgical churches have absolutely nothing in common... Their doctrines are completely contradictory to each other. They can’t all be true. To pretend that Roman Catholics, Eastern Orthodox, Oriental Orthodox, Nestorians, high church Anglicans, and low church Fundamentalist Protestants all share the same religion is simply nonsense on the face of it.”
First, I believe it is important to be respectful to others as much as is possible. I have many times in the past by being too harsh with those who hold different views, and that is something I am trying to correct and find a balance on. I feel that to accept the profession of faith by others at face value is not an ecumenical compromise. The few cases where the term “Christian” is used in the Bible refer to a derisive term that unbelievers gave the early followers of Christ. If someone calls themselves “Christian,” I can generally accept that label without feeling the need to know with absolute certainty if they are born again. The degree of confidence we have in our own salvation and that of those we know will be a determining factor in the degree to which we are able to build a close bond of friendship.
So, for example, I certainly feel at ease cooperating with various “Christians” who want to work together to promote a conservative candidate or a cause like the pro-life movement. But I might want to know a little more about the doctrine and testimony of a person who would like to meet up for Bible study. And in the case of forming a business partnership or entering into marriage, the Bible clearly says not to be unequally yoked with unbelievers. This underscores the necessity to evaluate if someone else is a genuine believer. But first and foremost we need to examine ourselves in this regard. That’s also a Biblical command.
I have frequent discussions about the Bible and Christ with people from denominations that teach and practice error. It does grieve me when believers remain in churches where the truth is not being taught. But the criteria for salvation is not attending the right church. Certainly, when a professing Christian continues to participate in false religion, whether doctrinally or in practice, this is very troubling. And it even begs the question of the sincerity of the profession of faith. But I still hold to that salvation is NOT contingent upon church membership. And true believers can be deceived doctrinally. Ultimately it will be Christ who judges who is truly His. In some cases I think people come to Christ in spite of the church they attend rather than because of it.
Make no mistake. I’m not minimizing the danger of false doctrine or religious practices. I’m simply observing the reality that churches that preach the true message of the Gospel and basic Bible doctrine still contain members or regular attendees who have never believed the Gospel message for salvation. In fact, this must be the case because we are not automatically born again just because our parents are. So, those who grow up in Bible-teaching churches still need the salvation experience.
Likewise, a person could be in an entirely false church and be a born-again believer. A child might have believed the Gospel due to hearing it from another child at school or in the neighborhood. But that child might attend a false church that denies the deity of Christ. A person might be converted in a church where even the leaders are not born again, but the reading of scripture and other content such as the songs contain enough of the message of salvation that they believe.
My opinion is that God will lead those who truly belong to Him away from false doctrine and religious practices to have fellowship with other believers and be under the sound teaching of the word.