The early heresiologists complained of the Gnostics that they taught that one's salvation lies in what one knows, rather than one's faith.
In my usage here, faith is different from belief; faith is intransitive, whereas belief is transitive. Faith means maintaining hope and trust, whereas belief entails an object: one believes "something," one doesn't just generally "believe." In my opinion there is no difference between "knowing" a concept and "believing" a concept.
Christianity rooted in
faith would be unitive; but Christianity rooted in
belief is divisive, because words are imprecise and spiritual concepts shift around as we examine them. An emphasis on belief becomes invariably an emphasis on hairsplitting:
homoousia vs.
homoiousia, filioque, etc. This turns the church into a "who's-in-who's-out" game based on one's concepts, rather than a "we're-all-in-this-together" game based on recognition of each other's faith. Therefore, so far as I can tell, many Christians in practice are guilty of the exact same error of which the ancient Gnostics were accused -- seeking Christ through defining of concepts rather than through faith.
Many Christians have both faith and beliefs. But it seems to me that an abundance of faith would make emphasis on beliefs seem unnecessary; when one has strong faith, whether one is Christian, Muslim, Jewish, Pagan, or what-have-you, that one is not overly concerned with the details of what other people around them believe, and furthermore, that one generally does not feel the need to question the validity of other people's faith
or beliefs. So I think emphasis on beliefs is indicative of a widespread crisis of
faith.
I've argued this point before, only to have it denied and the assertion repeated by proselytizers: I would be "saved" if I only professed belief in Jesus as my Lord and Savior; nothing more is essential. But typically it is not true that this is all I need, because many of the people who have tried to proselytize me tack on a lot of concepts which
they think necessarily follow. For example, they might say that if I do not oppose abortion I must not have "actually" accepted Jesus, and so on.
It frightens me to contemplate the idea of God operating that way: picking and choosing on Judgment Day among people with real faith but excluding some because they happened to believe in the wrong concepts. With so many contradictory ideas floating around, how could I
ever be sure I happened to choose the right collection of concepts to be "saved" and go to heaven?
Whether or not God works that way, many people do, and they use concepts rather than faith to play "who's-in-who's-out." Mormons usually find themselves on the excluded end of this, being told they believe in the "wrong Jesus." There is no bottom to this slippery slope; emphasis on "belief in the right concepts" versus faith is
inherently divisive.
It happens to Catholics too, sometimes, here's a case in point.
A Christian adoption agency that receives money from Choose Life license plate fees said it does not place children with Roman Catholic couples because their religion conflicts with the agency's "Statement of Faith."
Bethany Christian Services stated the policy in a letter to a Jackson couple this month, and another Mississippi couple said they were rejected for the same reason last year. "It has been our understanding that Catholicism does not agree with our Statement of Faith," Bethany's state director Karen Stewart wrote. "Our practice to not accept applications from Catholics was an effort to be good stewards of an adoptive applicant's time, money and emotional energy."
from Christian adoption agency snubs Catholics (thanks to
burkean for the link)