Contrary to the popular belief that elite global cities are extremely secular, they are often much more religion-friendly than commonly advertised. New York City in particular is very friendly to religion and may be what journalist Tony Carnes has labeled "the first post-secular city." In particular, there large Christian populations in immigrant and ethnic communities that can go completely unnoticed by many. There may be as many as 1.2-1.6 million Evangelical Christians in NYC, mostly in these under the radar groups.
The religious heritage and environment of each city is distinct, so blanket conclusions can't be drawn about their friendliness to Christianity. But it's a mistake to assume that these places must be highly secularized.
A Journey Through NYC Religions: http://nycreligion.info/
An Evangelical Revival in the Heart of New York: https://www.nytimes.com/2015/07/10/nyregion/central-park-festival-to-highlight-new-yorks-vibrant-evangelical-movement.html
Christian Cultural Center: https://www.nytimes.com/2016/10/16/style/reverend-ar-bernard-new-york-megachurch.html