Looking at Muhammad and what He did and said seemed like a useful starting point. The concept of Progressive Revelation shouldn’t be too hard to grasp. If you believe God Revealed Himself or made Himself or His Will known through both Moses and Christ then we have an excellent example of Progressive Revelation. What Christ Taught was founded on the Hebrew Bible.
You know I have an opinion on this. I think Jews have a very good reason to reject Jesus as their Messiah. He didn't fulfill the things in the prophecies. And, some things given as prophecies are taken out of context and were never meant to be prophecies. In other words, they are phony prophecies. One of the main ones I complain about is the "virgin birth" one from Isaiah. A virgin or a young maiden? Was it a prophecy or a "sign" for the King? I see it as a sign and that by the time the child reaches a certain age the Kings enemies will be gone. And they were. This kid also was to be eating some curds or something? When did Jesus do this? Never. And Christians don't use any of the context of the story. They only use and need the word "virgin". That ain't right and if it was the only time Christians did this, it would be enough to falsify their claims. But, it isn't.
So then Christianity did "progress" out of Judaism... and messed everything up. Jews, Baha'is and Muslims all say how Christians got it wrong. And I say it was very early on and even in the writings of the NT. So a progression or a religion with some made up parts that are false? Wouldn't that make it a false religion? You know all those things... Jesus is God. Satan and hell. people were born sinners and need the sacrifice of Jesus to save them and so on.
But I like some things about Christianity. I know people that can feel Jesus in their hearts. Lots of them have love and compassion for others. But then, some feel there is a need to do some Bible bashing and get people to believe before it's too late. So some Christians are great, but that still doesn't change the fact that Jews, Muslims and Baha'is don't agree with many of their major doctrines and beliefs. So a progression? To what? A religions with false beliefs?
So, the question for me is, why does it work? I usually add Mormonism to this question. They have beliefs that other Christians say are false. Protestants say Catholics have false beliefs. Yet people in all of them, if you asked them, know God, can feel his presence in their lives and believe and trust in the things their form of Christianity teaches. So why does it work? Because they believe. Kind of like self-fulfilling prophecies. They can believe in things others say are wrong, but if they believe it... it will work. It will seem as though their idea of God is true. And, things in their life and things that are happening in the world will verify the truth of their beliefs. But all of them believe different things.
Anyway, I don't see religions as a continuing progression but various and very different beliefs that change over time from within and from without. So please carry on with your discussion with Moz. I'm sure I will get a lot out of it.