Does this question not counterpoint the absolute nonsense that any religeon is superior to any other? The sad fact ,IMHO, is that there is far too little inter-faith/racial (aint they essentialy the same?), marraige or relationships. Seems to me that the majority look for and draw emphasis to differences rather than look at what we share. If there is a 'God' that is 'responsible' for what we are then that God would be saddened that we seek to find so many ways to divide ourselves.
On the physical side, in some faiths, inter family marraiges are responsible for terrible mutations. Is that right?