Both article 6 and the first amendment make it in very poor taste.
You may personally appreciate it, but suppose he had been quoting different religions texts. Say the need to nourish Mayan gods using sacrificial blood.
I worry that people are now so illiterate that they do not recognize that the "render unto Caesar…" quote is a historical basis for the division between church and state in the Christian world. Astonishingly, they view the Government citing the quote – the origin of separation – as a threat to separation!
I agree, but I think using this saying is within reasonable bounds compared to a coach leading school-affiliated prayer. The decision even left out the religious that followed.
You may personally appreciate it, but suppose he had been quoting different religions texts. Say the need to nourish Mayan gods using sacrificial blood.