Some day, probably in the world to come, we will know the truth and the truth will set us free. Until then I certainly don't depend on doctrine or ritual but on a simple faith, like Jesus called for, quick to acknowledge that my church(es) over the years - Methodist, Congregational, Presbyterian - never claimed that theirs was the one true religion. My guess is that we all miss the mark by a mile - well, by 1000K perhaps. But I don't fret. "I trust in God wherever I may be, upon the land or on the roaring sea...." A beautiful hymn sung at Dr. King's funeral in Atlanta, which I was privileged to attend.
I view feelings and/or pretensions of religious superiority as not all that different from those of racial superiority. Both have led to gross persecution and bitter bias and grave injustice, and both are evil in the eyes of God. "Many gifts, one Spirit, one love known in many ways, in our differences is blessing, from diversity we praise...." Another great hymn.
The world beyond will be full of all sorts of Christians, but also an abundance of Jews, Muslims, Buddhists, Hindus, etc. We will both laugh and cry as we think back to silly religious prejudices we had, mainly based on ignorance and one-upsmanship, and have plenty of reason to repent of our foolishness.
Meanwhile, God bless all posters and people of every creed. color and country. And those with no creed or sacraments, like the Quakers. In fact, if there were a Quaker meeting nearby and if the Quakers would only sing some lively hymns, I probably would be attending there today, at least often. Or, even join the Mennonites if I could only accept their quasi-fundamentalist theology. "I'd rather see a sermon than hear one any day, I'd rather have one walk with me than merely show the way..." Who wrote that? His name slips my mind. Ogden Nash, maybe?