(...Continued from above)
3) On the non-exclusivity of the Biblical message, I started with Jesus' words from John 10:16...
"And I have other sheep [beside these] that are not of this fold. I must bring and impel those also; and they will listen to My voice and heed My call, and so there will be [they will become] one flock under one Shepherd."
...and interpreted it to mean that people of other religions could be saved by virtue of Jesus' sacrifice as well.
There is also a passage in Acts 17 where Paul is in Athens and observes one altar, among all of the Greek idols and altars, with an inscription upon it to the "unknown god" (v. 23), and Paul is like (and I'm paraphrasing several verses here), "Ah, I see you are already worshipping Him, so let me tell you about this God that you do not know yet."
So to me, that's basically suggesting that God accepts worship from other religions, even if they don't have the same name for Him--and if you were to ask the God of the Bible which religion is most true and correct, He would most likely say...
"Religion that God our Father accepts as pure and faultless is this: to look after orphans and widows in their distress and to keep oneself from being polluted by the world." --James 1:27 (NIV)
No denominations, no religious figures or founders, no religion in the usual sense at all--just taking care of each other. If that's your religion, God accepts it as pure and faultless.
And while there's the notion in Christianity that you can't get to heaven without acknowledging that Jesus Christ is your Lord and Savior, there's also an awful lot of talk about being judged by what you have done in there as well. I think perhaps the concept that Jesus' sacrifice was indeed the mechanism by which any and all who CAN be saved ARE saved became conflated with the idea that salvation is anything other than the sole choice of God, and that what you DO is a better reflection of your salvation status than what you BELIEVE.
This is reflected in stories about good fruit from good trees in Matthew 7 and the parable of the sheep and the goats in Matthew 25, as well as the account of final judgment in Revelation 20.
"A good tree cannot bear bad fruit, and a bad tree cannot bear good fruit. Every tree that does not bear good fruit is cut down and thrown into the fire. Thus, by their fruit you will recognize them." --Matthew 7:18-20 (NIV)
You shall know God's people by their fruits--not by what they believe, but by what they do. It continues...
"Not everyone who says to me, ‘Lord, Lord,’ will enter the kingdom of heaven, but only the one who does the will of my Father who is in heaven. Many will say to me on that day, ‘Lord, Lord, did we not prophesy in your name and in your name drive out demons and in your name perform many miracles?’ Then I will tell them plainly, ‘I never knew you. Away from me, you evildoers!’" --Matthew 7:21-23 (NIV)
So it's not enough to believe in God or even to call Jesus "Lord." Salvation may have only been made possible by Jesus' sacrifice, and there may indeed be no other way into the presence of God--but just believing that is not enough to be saved. You are saved by loving God and loving each other, which fulfills the entire Law (Matthew 22:34-40), but you were only able to be saved in the first place because Jesus provided a bridge back to God (whether you realize that this is why you are able to be in God's presence or not).
Moving on to the sheep and the goats in Matthew 25:31-45 (NIV)...
“When the Son of Man comes in his glory, and all the angels with him, he will sit on his glorious throne. All the nations will be gathered before him, and he will separate the people one from another as a shepherd separates the sheep from the goats. He will put the sheep on his right and the goats on his left.
“Then the King will say to those on his right, ‘Come, you who are blessed by my Father; take your inheritance, the kingdom prepared for you since the creation of the world. For I was hungry and you gave me something to eat, I was thirsty and you gave me something to drink, I was a stranger and you invited me in, I needed clothes and you clothed me, I was sick and you looked after me, I was in prison and you came to visit me.’
“Then the righteous will answer him, ‘Lord, when did we see you hungry and feed you, or thirsty and give you something to drink? When did we see you a stranger and invite you in, or needing clothes and clothe you? When did we see you sick or in prison and go to visit you?’
“The King will reply, ‘Truly I tell you, whatever you did for one of the least of these brothers and sisters of mine, you did for me.’
“Then he will say to those on his left, ‘Depart from me, you who are cursed, into the eternal fire prepared for the devil and his angels. For I was hungry and you gave me nothing to eat, I was thirsty and you gave me nothing to drink, I was a stranger and you did not invite me in, I needed clothes and you did not clothe me, I was sick and in prison and you did not look after me.’
“They also will answer, ‘Lord, when did we see you hungry or thirsty or a stranger or needing clothes or sick or in prison, and did not help you?’ “He will reply, ‘Truly I tell you, whatever you did not do for one of the least of these, you did not do for me.’"
So here we have all the nations being judged--not just the Christians, but everyone--on the basis of what they did and didn't DO. Not a single question about what they believed--even those who thought they were "believers" were judged by nothing other than whether or not their actions followed the pure and faultless religion of love.
And again in Revelation 20:12-13, the judgment of all the dead is said to be on the basis of their actions and intentions, not about their acknowledgment of Jesus or any other "religious" belief.
"I [also] saw the dead, great and small; they stood before the throne, and books were opened. Then another book was opened, which is [the Book] of Life. And the dead were judged (sentenced) by what they had done [their whole way of feeling and acting, their aims and endeavors] in accordance with what was recorded in the books. And the sea delivered up the dead who were in it, death and Hades (the state of death or disembodied existence) surrendered the dead in them, and all were tried and their cases determined by what they had done [according to their motives, aims, and works]." (Amplified Bible)
So I don't know what else you're looking for to suggest a universal sense of inclusion of other beliefs in the Bible, but I think there's plenty of room for that interpretation.
4) and 5) I think I've answered already.