First of all, I'd like to draw your attention to Science magazine's article about paleontologist Stephen Godfrey (http://www.sciencemag.org/cgi/content/full/319/5866/1034) who had been a creationist until the evidence in the ground, logic and intellectual honesty led him reconsider his beliefs and conclude with evolution.
I went through a somewhat similar change very many years ago. You may be surprised to know that Darwin believed in something very much like Intelligent Design before his travels changed him.
So here's a little hurrah for courage and intellectual honesty!
Now... to address Intelligent Design's place vis-a-vis science. It is established that ID is not science because:
1- It is not falsifiable (since ID refuses to qualify the creator or his methods or motives)
2- ID relies on supernatural causation
3- There is no direct or positive evidence for it. Most evidence "for" ID consists of:
a) finding gaps in evolution or the fossil record
b) trying to falsify evolution.
Gaps in a theory are not falsification. Gaps exist in physics too. It would be nonsensical to say that physics is false because of the gaps that exist so far in it.
Another issue is that according to the scientific method, falsification of evolution does not lead automatically to ID. It may lead to an alternate theory of evolution (such as Lamarkian or some other mechanism) or other different things. There is no strict duality between the current theory of evolution and ID.
Hence falsification of evolution is not evidence for ID. It should be noted though that most creationist attempts at falsifying evolution have been very well answered by the scientific community. This Nova documantary will give you a small idea of the debate: http://www.pbs.org/wgbh/nova/id/
Many of you may have looked at the debate from the lense of creationist or ID polemicists, so be honest and take a peek at the position of science in its own words.
But let me get to the point (finally!).
Science is NOT about getting to the absolute truth no matter where it leads you. There are rules. These include:
1- Falsifiability
2- Natural causation
3- There must exist positive evidence FOR the theory
4- All science is tentative and may be revised or elaborated in the light of new evidence
So, what would science look like if ID was correct and evolution was wrong? Well, basically evolutuon would get discredited and we would NOT HAVE a scientific theory of speciation.
But ID would still not be science. It would belong in philosophy class and church. ID can never be science even if it is correct.
Even if all variants of evolution were falsified and we had no alternative, at best, a science text could say something like: "We do not have an explanation for speciation but religions posit a creator. Now on to fungi..."
That said, in reality evolution is a very strong and robust theory and is considered by the vast majority of biologists and paleontologists to be a very good explanation of speciation.
Finally, science does NOT say there cannot be a God. Evolution does not require atheism, so before getting emotional, consider that.
Ofcourse, there are those that will object and say that evolution is merely speculation that fits tghe evidence, and that ID or some flavour of creationism fits the evidence equally well.
But I think if you calmly look at the logic and explanations of both sides and read the scientific explanations and answers to creationist criticisms from their sources. If you read the actual scientific material, and not through the lense of ID-ists presenting it to you, I think you will clearly see that Evolution is the correct interpretation of the data.
That's why Darwin, the head of the Human Genome Project (who is devoutly religious), Godfrey and many many others all came to the same conclusion even though all of these people had good emotional and religious reasons to WANT creationism to be true.
That's why the vast majority of scientists, including religious ones, favour evolution. The evidence is vast. Read science directly, not through creationist polemicists.