I really think it is an unanswerable question. I don't think it is possible for us to know the plan of salvation by God for some one else. I think the only real distinction you might be able to make is if they would be considered "Christian" in their theology.
Sorry if this isn't a very helpful answer, I just don't think anyone can really answer the question, but God.
If this was true then how could we preach the gospel if we don't know what it is?
There are some facts that one must believe to be saved. They have to believe something.
And that much must be in the preaching. I do not think the entire content of the gospel needs to be in one message. A person may have to hear several messages before they hear and know what they must believe.
then of course there is the issue of credible profession. What must they know and believe for a session to admit them to membership.
Is this the same content or more or less?
Personally I love the Sum of Saving Knowledge made by the Westminister Assembly and was originally included in the Westminster standards books.
-----Added 3/30/2009 at 12:19:53 EST-----
True. I guess I need to rephrase my question, because you're right,
we can't determine if someone else is saved. So here is my revised question: "What must someone believe to be considered an orthodox Christian? What are the basic doctrine's one must adopt to be a member of the visible church?"
I think both are valid questions but yes they are two separate questions. The real question is are they 2 separate answers?
-----Added 3/30/2009 at 12:29:59 EST-----
I think they are great questions and I think the church is not clear on them today.
Manyy say for sure the second is session controlled. ie they do not want to confessionally dictate what specifics one must believe and profess to be allowed membership and recognized as a member of the visible covenant believers.
And for some it is age dependent. They believe less is required to be believed if one is younger.
And I do not think that we have the whole story in scripture passages such as what must I do to be saved. ...
There was more told to the person that they had to know.
Also consider that to the JEw who had been in the covenant and had been educated quite a bit they were told by Peter to repent and believe.
Not much needed other than to repent of not accepting Jesus as the messiah.
And to believe He was.
They had been taught about God since children, seen the sacraments and types, and knew he law, that they were sinners etc.
Whereas for a Gentile with no background more explanation of God, His law etc. was needed. Like what Paul preached in Mars Hill.
So I do agree there is a lot of content to preaching the gospel it is not some short snippet as the evangelicals of today would have us think.
Receive Jesus, Pray this prayer, come forward and profess Christ as savior etc.
I think there is more one must know and believe.
Let see what others say.