For the faithful servants of each religion we have no problem, the scripture given to each of us specifically states something solid about what constitutes an unbeliever (hence all the we are right and you are wrong discussions). Where difficulties arise is that they cannot all be correct, can they? Either it is 'a must' to place a partner with G-d or it is 'forbidden'.
Or perhaps, as I believe, we are all given a seperate path by G-d to test our faith. You will never convince me that Jesus (pbuh) was the son of G-d or that he is the only way to G-d and I will never convince you otherwise. Perhaps that is not what is important. On Judgement Day we will all be accountable for our deeds and the faith in our hearts, not in how many people we convinced we are right and they are wrong.
That's the kind of thinking that I like. It is the idea of not biasing oneself in either direction to say Jesus must be seen as Son (or part) of God or that Christians are wrong in their beliefs. I like the idea of not having to aggressively push my ideas on others as if I have to somehow prove myself but at the same time (the opposite) I don't want to think I'm somehow deranged or disturbed because of my beliefs.
As many of us know, the doctrine of the Trinity and the idea that Jesus is a part of God is really just a way of explaining something vague or "unclear" in the Christian New Testament (NT) -- Christianity's concept of God. The idea that Christians "assign partners" to God is a common depiction Muslims have of Christianity's concept of God. There is a possibility that Muslims may be right, that we do "assign partners" to God. On the other hand, what if Christianity's concept of God was misunderstood, not just by Muslims, but also by Christians themselves? What if this idea of "assigning partners" to God is only derived from Christians' own misconception of Christianity rather than Christianity itself being "broken" (so to speak)?
Is Christianity's concepts wrong? Most Christian beliefs arise out of an already-established culture where those beliefs are promoted and upheld. The "real Christianity" is more likely to be found in the text used by Christians. The "already-established culture" is where most people start learning about Christianity. A lot of people assume that this already-established culture defines Christianity.
The text used universally by (most) Christians around the world is the NT. Our concept of God is drawn from the hints in the NT about how God might be understood. The NT does not appear to define God. I think this is where the problem begins. Christians try to use a text that doesn't define God to go ahead and formulate a definition of God.
A text that doesn't define God treats God as an abstraction. The NT therefore treats God as an abstraction. Of course, the NT does contain hints that describe how the early Christians understood God. If these "hints" define "parts of God," they could be used to formulate a definition of God for Christianity. But there's a chance that these "hints" were never meant to define God either. If the "hints" don't define God, even parts of God, then what are they? Hints that don't define God, or parts of Him, but have something to say about God, or a person's interaction or encounter with God are more likely to be experiences of God rather than definitions of God. That may mean that Christianity never really had a definition of God. What you read in the NT, instead, is an experience of God. Does Christianity assign partners to God? Moreover, is God, in Christianity a three-in-one? These statements depend and rely on the idea that Christianity had a definition of God from the start.
That is not to say that Christianity doesn't have a "concept of God." Christianity may not have a "definition" of God but it may still have a "concept." The concept is not a definition, but an experience of God. The point here is a distinction between an abstraction and a concrete concept.
Christianity assigning partners to God? I've thought about this for quite a while. I think it unlikely that, Christianity, emerging from a Jewish culture, would have, as is commonly depicted in Islam, "assigned partners" to God. Because Judaism is the worship of one God, it would have been unlikely for Christianity to have gained ground if it had promoted such a belief. By the time the Romans came, the people of Israel had reformed, gotten rid of idol worship and became more devoted to Judaism and its concepts.
I don't see Christianity as flawed. Instead, I see our beliefs about Christianity as flawed. We believed that we needed to define God because by defining God we gave ourselves a sense of certainty. The logic behind a definition of God gave us a sense of certainty, which leads to the Christian notion of salvation. The notion of salvation is the idea that there must be some level of certainty in a religion.
This is where I think we parted from the early Christians. The early Christians were inspired and driven by an experience of God, and therefore didn't need to define God because the experience itself was enough to give them a sense of certainty that they had found God. They personally sought God. Our pursuit of definitions of God may mean that we are not as God-seeking as the early Christians and probably not as close to God as they had been. That is perhaps the problem. Jews and Muslims don't seek to define God as much as Christians. They treat God as an abstraction.
As Christians we've conditioned ourselves into believing in concrete definitions. We seem to distrust abstractions.