My question is really whether one who does as many unselfish loving acts as Mother Teresa would be turned away from heaven for the lack of water and the sign of the cross.
Do you think she would be?
With respect, it is not the ‘unselfish loving acts’ which ‘fit us’ for heaven. Many people do great works which ‘appear’ charitable but which are done for the ‘building up of the person doing them’. Jesus noted this in Scripture. Remember the pharisee who “gave tithes on ALL he possessed?” I’m sure that on the outside he looked wonderful. . .yet was he?
As far as the ‘turned away from heaven for the lack of water and the sign of the cross’
I believe you have been told that baptism, the ordinary means for salvation, is not ‘solely’ through water (ordinary) but through God’s mercy can be through blood or through desire. So ‘limiting’ your comment to a very specific and slightly derogatory notation of ‘lack of water and sign of cross’ shows you either haven’t considered or known of the other options, or that you are trying to turn baptism into a ‘legalism’ ploy in which to fault the church. It’s a strawman. The Church isn’t ‘legalistic’ but that does not mean that it abrogates all law.
A person who through no fault of his own did not KNOW the Catholic Church, who does God’s will (which is written on the human heart) to the best of his knowledge and capacity, LACKING knowledge of Christ and/or His Church, MAY be saved, and the way that person is saved is through the Catholic Church. It is a mystery, but that is what God has revealed. It has nothing to do with how ‘pious’ the person appears, or how many ‘good deeds’ a person does as if ‘good deeds’ were the sole criterion for heaven. It has everything to do with the person’s heart and soul, and with God’s judgment and mercy and teachings.
IOW, GOD decides who is saved, how and why. Not us.