once saved ...always ...
I believe once properly saved by fully obeying the Gospel ...
hearing the word, believing that Christ is God, repenting of sins, being properly baptized, and continuing to serve and love God, one need not ever be lost. Our subsequent failures and weaknesses will not cause us to become "unsaved". God and Jesus will continue to faithfully stand by us and pick us up, much as a loving parent will pick up a child who falls trying to learn to ride a bicycle.
However, if we were to curse God and willfully reget Jesus after previously being saved, I believe that would cause us to be lost.
rt