I haven't read any of Spinoza. He has been a vague blot in my periphery until a moment ago when Hitchens caused him to move into a closer orbit by dint of his mentioning that he was excommunicated from the Jewish faith. According to Wiki, there may have been some collusion in the Roman Catholic Church to hasten that eventuality. Either way, his works were prohibited by the One True Church.
In trying to understand where theology might go, and central to the epistemological modesty of my conservatism, I have long maintained two arguments that now suddenly appear to me to be in conflict. They are the one matter which is that man's nature is fixed although his orientation to the world and his understanding of himself in the world may vary greatly. The second is that the Church, and Christianity is unique in that it updates itself to make adjustments it must in its imperfections and understanding of the world.
If it is therefore the case that Christianity gets better and mankind stays the same, then it brings into question whether or not any version of Christianity serves man's eternal soul. For if the soul is eternal and fixed, in the image of the Creator, then any Church with claims on that soul must have the method, and that method too would be fixed. (Perhaps that's what the Methodists are on about.)
It might be argued that the Church possesses a superset of the method of it's aim with any human soul and its improvements are mere enticements to a changing population. There is thus that question of what it is the essential and minimum function of the Church. That would be what we should attend, with the understanding that the rest is all just evangelism.