Why trust them?

At last the Church of England has decided that gay couples should after all be allowed to marry, this is good news for everyone it affects of course but surely this is a further nail in the coffin of the church? Allow me to elaborate.

We are told by these people (i.e. the Bishops that sit in our Parliament) that the source of our morality is or should be (their) God and is therefore objective, so what are we to think when this morality changes? It strikes me there are only 4 possible options.

1. There is a God and he cares about what people do with their genitals but sometimes changes his mind. This should be a terrifying proposition, here is an all powerful deity who sends you to paradise or purgatory depending on rules that he can change at any time? What about all those poor gay people throughout history who have already spent hundreds or thousands of years in hell, what compensation do they get?

2. There is a God who cares what you do with your genitals but the priesthood has misinterpreted him. Such a revelation should surely shake your trust in organised religion to the core? it means that the church can get God's will totally wrong. What if he really made genitals for a reason and we're all supposed to use them in joyful ways and the communication between heaven and earth is just totally garbled? We could be committing all kinds of omissions and errors and be completely oblivious to them.

3. There is a God who really doesn't care what you do with your genitals. So this would mean that all the angst and psychological pain suffered over the years by millions has been a huge unnecessary distraction and exists solely in the minds of the self appointed religions morality monitors, again, why trust them ever again?

4. There is no God, no afterlife, no eternal punishment or reward. The priests and shaman have been making it all up all along and using an invisible super-being to scare people into serving their own earthly whims. Religious people have been "had", so, rise up and throw off your chains!

I wonder which is more likely?