Yes, this was my experience in Sunday school, (ahem) a few years ago. One little ditty that we were taught to sing went:
One door, and only one, and yet its sides are two;
Inside or outside on which side are you?
One door, and only one, and yet its sides are two,
I'm on the inside! On which side are you?
Not only was it set to an earworm-worthy tune, it enforced a strict division between 'we' and 'the great unwashed', living no doubt whatsoever which gang was better.
Through the years I've also had to learn the lesson that Peter learned in Acts ch. 10. The dividing walls that we too often set up are pointless and useless in God's sight.