One of the things that creationists often say that really annoys me is that evolution and creationism are not all that different in that they both rely on the same facts and observations, but come to different conclusions because they use different starting assumptions. Biologists, they claim, begin with the assumption that natural selection, common descent and descent with modification are all real phenomena, while creationists begin with the assumption that the Bible is the inerrant word of God. They posit that, because the two groups use different starting assumptions, they interpret the data differently, in a way which confirms their preconceived views; when a biologist looks at a giraffe, she sees the byproduct of billions of years of evolution, whereas a creationist sees obvious design.
This claim is absolute rubbish. Anyone who makes such a claim is exposing their incredible ignorance of the scientific method. In fact, such statements run completely contrary to the way the scientific method is supposed to work!
Generally, the scientific method works like this: you gather observations and empirical data, and from analysing the observations and data, you draw out general conclusions which explain all of the data. In other words, science does not start with any unfounded assumptions; it begins with the data, and from the data determines general principals on how the world works. Scientists do not begin by assuming the nonexistance of God - God doesn't even factor into the equation for the most part. In the case of evolution, biologists do not begin with assuming God does not exist and then interpret the data in a secular manner; instead, biologists determine from the data that species arise from a purely naturalistic process, and God's non-involvement follows as a natural conclusion.
Creationists, on the other hand, follow such counter-scientific principals to the tee. They start with their supposed conclusions - goddidit - and then ask "What facts can we find that support our conclusion?" To creationists, facts follow conclusions and not the other way around. They begin by assuming that the Bible is the inerrant word of a supernatural entity, and then stretch, skew and distort any facts they find to try and make them fit into their biblical beliefs.
The idea that science and religion simply begin by making different starting assumptions is antithetical to science. This is a big part of the reason why "creation science" is such a huge joke.