Is it possible to be A Christian, and to practice another religion?

Q: Is it possible for be A Christian, and to practice another religion? 

A: Yes it is possible, here-and-now.... 

But it was not always possible. 

In the past (and even today, in other places) someone who recited a creed would believe that creed. More exactly, he could not say it unless he believed it; because saying was believing. 

In earlier forms of human consciousness; thoughts were words, words were thoughts; and words were things. 

But now, words are not things: words can mean other than they say, or mean nothing. 

Now; thoughts are distinguishable from words, and words are distinguishable from actions. 

This is, indeed, normal - and indeed required. Therefore...

Modern Men can do Christianity, but not be a Christian; and can be a Christian but not do it.  

So it is here-and-now possible to practice any other religion, or none; and yet be A Christian...

And/or be a Christian and/yet practice some other religion, or none. 

Which is, if you think about it, when you look around at The World, very much for-the-best; which is, presumably, why God has made things thus.