1. Eternal security is a concept which Christ assured those who had been given to Him by the Father. Your confession, decision, or ceremonial celebration have little to do with whether the Son has adopted you or not. Notice in Matt. many will be outside of the door, pounding to get in having done all kinds of deeds for Christ. He says, "Depart, I never knew you." Not, "You never knew Me." I have no idea if He adopted you. Too much "evangelical" ferver has been attached to Billy Graham Crusades & "decisions made for Christ" to the neglect of a clear understanding of the Gospel.
2. Your movement toward an organization which traffics in self-determination is a substantial bit of evidence that you never really understood the Gospel in the first place. Otherwise you would understand how this particular organization does not represent the Gospel of the Scriptures. There is no question that they claim the numbers, the power, the authority and all of the rest...they just lack Christ. If this does not make you nervous, then it might be good indication that you were not among the elect to begin with and you are simply seeking others of like mind. It is done all the time. Read the entire letters to the Romans, Galatians and Ephesians and notice that there is no transaction given among men by which you may be saved. It is unmerited grace granted to those chosen before the foundation of the world. If the Father has given you to the Son, then you are safe irrespective of how screwed up the organization you join really is. Joining them is not advisable, but it even they cannot keep you out of His care...if He has laid hold of you.
Self-determination???? Not in the Catholic Church. Pelegianism and semi-pelegianism were rejected a few years ago if I remember correctly. I teach spiritual theology, using a text by Fr. Garrigou Lagrange (who directed JP II’s doctoral dissertation)—he is pretty well as establishment as you can get within the Church. It is spelled out quite clearly that there is a continual stream of grace from God that we can cooperate with or not. If one is cooperating with grace, that is not self-determination, and if one isn’t cooperating with grace, one isn’t headed in the right determination.