Ice Cube Molds and Christians

This will be  a super short post but I had this idea a few nights ago while driving home from the movies. I know that somewhere in the bible, it says that we are supposed to be in the world but not of the world. my though is similar to this. what if as Christians, we are like ice cube molds? or more like...water freezing. see, when you put water in any kind of mold, it takes on the shape of that mold, yet it is still water and it does not become that thing, it's just...shaped like it. while the analogy does have its limits, what if Christians were like that? what if when we go somewhere, we do our best to taken on the shape of the culture, of the environment, etc. but if stay water? we don't become that thing. I know this problaly is not making a whole lot of sense but it is a thought that I had. when I go to China, I am going to do my best to...take on the shape of Chinese culture. I will try to follow their customs, learn their language, etc. yet, like we were told in orientation, I will never be able to become Chinese, just like the water does stop being water and does not become what it takes on the shape of. water is a good model for Christians I think. water takes on the shape of whatever you put it in, yet it still remains water, just in different shapes.