The Gospel is liberal because Jesus denounced the clergy of his day. It is why they left it in Latin, so the people would not get any ideas about reform. Once it was put into the venacular, clericalism was doomed. Why would progressives want a secular gospel? We want teachings to not disregard scientific truth, but that is not secularism. We want publicly paid Catholic schools as much as any Catholic, but with unionized, certified teaches.  Humanist? Jesus was a humanist (gentle, humble of heart, morality for our sake, not his) and no Catholic progressive is atheist.  Marxists, maybe, but not all Marxists are atheists. The best ones are believers. It is a much more powerful message. Quit speaking soundbites.