It seems to me as if when we see people as created by God, and as being whom God has an interest in making happy for an eternity, then we will be more, rather than less likely to take their interests seriously here on earth. "Endowed by their creator with the right to life, liberty, and the pursuit of happiness. "Endowed by evolution with the right to life, liberty, and the pursuit of happiness" makes no sense whatsoever.
Christian homophobia, for example, has to be limited by the fact that, given Christianity, homosexuals are human beings created in the image of God for the purpose of eternal salvation. That are not just biological accidents doomed to drop out of the gene pool since they can't reproduce.