I would say that the best way to overcome such resistance is to lead the way. If you stick to writing tests, you are very likely to gather empirical evidence that it is a good thing to do. Hopefully your code will contain fewer bugs, the bugs will be quicker to locate and resolve and so on. If the other programmers in the team has the least interest in quality, they will probably also become interested in your approach.
My experience is that it is very hard to force developers into testing, but that they get a more positive attitude after seeing it around for a little while, and eventually move over to testing more voluntarily.