On Liberty by John Stuart Mill Chapter 2 Page 102

exerting themselves to promote. I much fear that by attempting to form the mind and feelings on an exclusively religious type, and discarding those secular standards (as for want of a better name they may be called) which heretofore coexisted with and supplemented the Christian ethics, receiving some of its spirit, and infusing into it some of theirs, there will result, and is even now resulting, a low, abject, servile type of character, which, submit itself as it may to what it deems the Supreme Will, is incapable of rising to or sympathizing in the conception of Supreme Goodness.

I believe that other ethics than any one which can be evolved from exclusively Christian sources, must exist side by side with Christian ethics to produce the moral regeneration of mankind; and that the Christian system is no exception