Which isn’t to place the burden of proof, for the alleged baselessness of the sacraments, on the agnostic, or unbeliever, but only to say that, to the extent that the believer can dwell in their belief, and not be engaged, at every given moment, in the work of evangelism, neither is the burden of proof for the reality of the sacraments on them. Though of course that reality, if indeed there is one, is so embedded in the spiritual realm that the very idea that it could be ‘proven’ is a non-starter, of which even an evangelist is aware, and has no intention of denying.