Yes, the stamps on display are for purchase. Many hang on a pegboard display and many are special edition collector sets. The display is 4'x8'. You can reach out and take them to a regular clerk or go to a register where stamps, postcards, and shipping supplies are sold.
Commercial displays of Christian icons do not convey any message of spirituality, nor religiosity nor even feelings of holiness for me personally. I have to go to God in prayer for that.