I don’t think I agree with this quote.
The greatest single cause of atheism in the world today is Christians: who acknowledge Jesus with their lips, walk out the door, and deny Him by their lifestyle. That is what an unbelieving world simply finds unbelievable.
I guess it depends on what he means by “their lifestyle”. Here’s the thing; I actually disagree with the idea that Christians who cuss and party are what drive people away from God. I don’t think nonbelievers want religious people who are goody-two-shoes, they got enough of that from the Pharisees. In the time of the Gospels, it was actually the religious, “upstanding” folks who drove people away from God.
This saying is well-meaning, and it is pointed at hypocrites, but I think the idea of the quote in itself can make hypocrites. When we believe that our personal holiness is what draws people to God, we don’t desire to be holy, we just desire to appear holy. Personal holiness is important, but it needs to be driven by a love for God and for other people.
In short, I don’t think it is our personal holiness that draws people to God, at least, what we tend to think of as “holiness”. I think it is love for God and others.