My own view, which does not rely solely on religious faith or even on an original idea, but rather on ordinary common sense, is that establishing binding ethical principles is possible when we take as our starting point the observation that we all desire happiness and wish to avoid suffering.
In the past, the respect people had for religion meant that ethical practice was maintained through a majority following one religion or another. But this is no longer the case. We must therefore find some other way of establishing basic ethical principles.