Eternal Security and Traditional Demoninationalism

Being the pastor of a traditional church, in which tradition I have no background, poses its own set of challenges and unique rewards. One of the challenges was discovering that our Mennonite heritage taught us that one could not be eternally secure (a challenge). I think part of that is the result of taking a few verses out of context that seem to point in the other direction. Recently the subject of biblical adoption was discussed. To me this is the clincher regarding the old cliche "once saved, always saved." Without exegeting those passages that address adoption or discussing the cultural position of adoption in the first century, let it suffice to say that an elder recently said that it was that subject that settled the issue for him; one can be sure of the security of his eternal salvation because he is eternally adopted and cannot be unadopted (a reward).
Today while considering Rom 8:38-39 I realized I have not explained this accurately to our congregation. I normally phrase it to emphasize that nothing I can do can ever make God stop loving me. Though that is true, that is not the point being made. It has to do with the word "separate." Just a few words from Thayer's bring greater insight to its real meaning: 1) to separate, divide, part, put asunder, to separate one’s self from, to depart 1a) to leave a husband or wife 1a) of divorce 1b) to depart, go away. It could be said that Christ is telling us that no matter what, NO MATTER WHAT, He will not divorce us or let us divorce Him. That does changes things a bit; well maybe more than a bit. When considered in the light of Eph 1:4-5 it is seen that the believer in Christ has entered into a Father/child relationship that began in the Father's love. Pretty mind-boggling trying to figure out those verses. The same love that determined I was chosen and adopted is the same love I cannot be "put asunder" from. So, my salvation is based on His eternal love for me from which He will not allow anything to remove me. With eternal security settled, and that was fairly easy, the issue of grace has not been understood well either with us. But that is for another time.