Are you 100% Christian?

I love this quote from C.S. Lewis:

"The world does not consist of 100% Christians and 100% non-Christians. There are people who are slowly ceasing to be Christians but who still call themselves by that name…There are other people who are slowly becoming Christians though they do not yet call themselves so. There are people who do not accept the full Christian doctrine about Christ but who are strongly attracted by him that they are his in a much deeper sense than they themselves understand. There are people in other religions who are being led by God’s secret influence to concentrate on those parts of their religion which are in agreement with Christianity and who thus belong to Christ without knowing it."