(Part 2)
Regarding the prior, my point is simply that the Gospel message, while stressing love, stresses even more a repentance and, secondly, that the mass itself is a duty of the believer regardless of any doubts, "Faith is the substance of things to be hoped for, the evidence of things not seen" (Heb. 11:1) or, as Aquinas would have it, “Faith is a habit of the mind whereby eternal life is begun in us making the intellect assent to what is non-apparent” (2a2ae, 4, co.).  One may certainly choose to dissent, for various ostensible reasons, from attending the mass, but those "reasons" seem to require specific accidents of liturgy - such as the holiness of the priest, a good homily, or "music I like" - and are, therefor, evidence of a lack of faith; at least as presented in Scripture (see, also, all of the verses citing "testing" God).