People change, it is not about being atheist or not, it is about being human. For example, I have been a vegetarian for over 10 years, I do not eat normal candy, I do not drink coke unless I have a bad stomach... all these are choices that I have made in my life, changes that I have chosen, they are not a result of what deity I believe or not believe in.
Change is a neutral concept. It does not have to be bad, just as it does not have to be good. Change is a part of life. Without it, our lives would be so much duller.