Without conditions, Health. Even if there is a frei Yid, whom you can not make totaly frum, but you can convince him to fast on Yom Kippur and not eat chomets on Pesach, you have to do it. Mitsvos are a chiyuv for anybody born a Jew. Find me a Rov who would agree with your opinion.
And what do you suggest we do with FFBs who are not ehrlach and create problems? Make them OTD in gantzn and expel them from the community? What you are saying is so totaly off!