I personally dislike the term cultural Christian because it implies that western civilisation is based on cultural values inherent to Christianity.
Remember the last 'witch' was killed in Europe in 1782.
Most European countries began separating church and state in the 19th century, IMO due to The Enlightenment in the 18th century.
For me western values is based on the last 200 years of the progression of secularism and humanism, but modern Christianity has absorbed some of those values and pass it off as their own.