I think the data overwhelming disprove your theory. Christianity has not been the dominant worldview in the west since at least the mid or late 1800s. Arguably you could take it back even further, to the Age of Enlightenment. But whatever. What has happened over the same span? The ongoing spread of democracy and gradual disappearance of authoritarianism, the granting of human rights to broader and broader classes of people, general decline in war and violence, general decline in torture and cruel and unusual punishment by legal systems, widespread abolition of slavery, growing acceptance of ethnic and religious diversity, etc. There are always exceptions, pockets of conflict or violence or corruption in any society. But the overall trend is clear. As it turns out, people don't need Christianity to find meaning in life, or to be decent and moral, or to feel a sense of connection. It's just that how an individual goes through life is no longer dictated by some dominant religious institution.