I guess the same reason why Christians, on the whole, no longer reject values which have come from secular society since the enlightenment:
I think you need a new history book, my friend :
Christians have been inimical to slavery from the first. In the Scriptures already there is a debate about the status of slaves in the context of Christianity, and the rule was laid down that slaves are to be treated not as private property but as the children of God, Who is the Master of both the master and the slave. This emancipation was a boon for Christian slaves who also had Christian masters, for it meant they were to be treated not only as co-religionists, but as persons created and loved by God, and it insured fair and ethical treatment in the relationship. They were no longer property in the strict sense of the word, but persons with rights before God.
Furthermore, as early as the 16th century the Church ; namely, the Pope, became critical of the developing slave trade and asserted that all peoples were human and none were to be thought of as mere property. Again the Pope stressed for the correct, fair and - above all -
just treatment of persons, and binded this on the conscience of all Christians masters to treat their slaves appropriately, especially if they were also Christians, which all persons were eligible to become, regardless of race or nationality.
Democracy did and does not to this day have a consensus support even among secularists. Most people accept a limited, republican and constitutional form of government. Communists, for example, rejected democracy and they were utterly secular.
Please produce evidence that Christians fought against this.
abolition of legal protection for men who rape their wives,
Please find, once more, Christian opposition to such a heinous and unthinkable thing as rape.
the right for workers to organise and combine,
The Church supports this. Before unions there were workman’s guilds and the Church, once again, entirely sanctioned this.
Vague and useless unless defined. No person would ever be forced to be baptized or engage in any Rite of the Church against their will. The Church fought to ensure this.
allowing immigration of people from non-Christian cultures,
No idea what you are even thinking of here.
abolition of established religion etc.
You are kidding, right ? Few secularists, save for communists (which is still an inherently treasonous philosophy) advocate for the abolition of religion ; furthermore, of course we are going to resist such a brazenly evil agenda.
Tim