What is "religiosity"? If the measure of religiosity is "participation in religious services", are we even measuring the same thing when participation can vary

What is "religiosity"? If the measure of religiosity is "participation in religious services", are we even measuring the same thing when participation can vary all the way from watching Jim and Tammy Faye Bakker on TV, to being blessed by the Pope in the Vatican, to receiving alms from Mother Teresa on the streets of Calcutta, or completing a Scientology audit graduation on a Friday?