Oh how I wish the recently demonstrated Higgs Boson, which bestows mass on particles, had never acquired the moniker the 'God Particle'. I suppose there is one benefit: it increases the attention and coverage about a very cool and significant question, just solved, in particle physics. But it does so with the false implication that this has anything remotely to do with God when in reality it counts neither for or meaningfully against the case for a deity.
There is a precedent here. Many religious people are quite happy to jump on the bandwagon of the Big Bang theory as being the moment of creation they had long asserted happened. Even the Catholic church has, after a few years, accepted the big bang and internalized it as part of their own worldview. Undoubtably, the Higgs Boson will be used in much the same way, especially because it already has the name attached to it, where people will point to it and say that it is God working in this universe, bestowing mass on particles.
It helps, very, very slightly, the atheist position. A common class of arguments for God essentially work by defining it as the God of the Gaps. Whatever science says is considered true, but when science does not know something, whenever there is a 'gap' in our knowledge, God is asserted to have caused it. Evolution might be accepted, say, since there is lots of evidence for that, but abiogenesis, which we understand very poorly, must have been caused by God. Every time we increase our knowledge of the world, as has been done with the Higgs Boson, we necessarily close the size of the gaps, giving God a little bit less space to work in.
We can sometimes have surprisingly profound conversations with children. Everyone is familiar with the infinite regress where the child asks, in response to every answer, 'Why?' that continues until the tired parent finally retorts 'Because!'. This is not far from how our epistemology is forced to work. We can always ask questions about why the universe is the way it is, and try to explain it in terms of ever more fundamental facts, but at some point one has to throw up ones hands and simply explain that we have reached a level that we can accept as true, but cannot justify further.
This is the reason that no amount of gap closing ever really helps us. Even though the Higgs Boson may answer the question 'what causes mass?' it only pushes the heirarchy of whys down one level; the next question will be undoubtably be posed: what causes the Higgs Boson? As of yet, since this has no explanation in terms of yet more fundamental causes, we must retreat to the position that this is simply how the universe appears to be. This 'gap' can always be explained, by the religious person, to be caused by God. Ironically, the hierarchy ought not to stop there and one should ask 'what caused God?', but this has rarely dissuaded the religious person in the past and I can hardly expect it would now (for more on the infinite regress problem, click here).
Scientists also dislike the moniker because it gives undue importance to this particular particle. It is indeed a momentous discovery, as it is the last major particle predicted by the Standard Model of particle physics and confirms in a major way the veracity of the Standard Model. However, many important questions remain in theoretical physics and we are far from saying we understand the universe. Further, there is not really a meaningful metric in which this particle is vastly more important than those that were discovered before it and do other things of importance to our universe. So it is bequeathed with this special status that it does not quite deserve.
As someone with a degree in physics, I have always hoped that we would not find the Higgs Boson, at least from an aesthetic sense. I like the mystery of the universe, and I like the idea that the questions remain much bigger and deeper as would have been the case if the Higgs Boson had not been found in the predicted range. We would have had to keep exploring and searching for a model beyond the Standard Model. And, of course, we do have to keep exploring to answer the questions that are deep and mysterious and remain despite this. I have a love hate relationship with the idea that the universe is "solved", even if we are far from that yet.