yeah, this is a common argument I have with religious people, especially during our recent plebishite on marriage equality. They oppose marriage equality, but eat shellfish etc. They pick and choose, in other words, they have their own beliefs and use religious texts to back them up but it is fine for them to ignore the bits that don't suit them personally.
What bothers me most about it isn't whether they're placing themselves above their God but in how they filter and cherry pick their morality and yet claim that they have objective truth and morals while non-believers are inconsistent in our morality. It's frustrating to hear them say one part of the Bible is valid and another part isn't, and to explain that certain things in the Old Testament can be disregarded because there was a new covenant but other parts of the OT must be adhered to, and yet claim 100% objective morality from divine dictate. It's like "1984" doublethink.