For all eternal security proponents who reject infant damnation, the same baby that would have gone to heaven if he died, when he gets older and sins, needs to be saved (or born again) because he is now on the road to hell. Hence, that saved person at baby age, later in life lost his salvation and needs to get it back or into hell's fire he will be thrown.
With this in mind, such eternal security (once saved always saved) proponents don't really believe in eternal security as they adamantly teach, but they have never come to realize this fact. Again, the once heaven-bound person becomes hell-bound and needs salvation, in denial to their own unscriptural and contradictory theology!
A final thought: It is also a fact that many eternal security proponents show they reject eternal security when they declare people such as those of us who oppose their teaching, are unsaved. Over the years, we have often heard that we need salvation merely because we reject eternal security.
Hence, they are contradicting their own belief system because if we ever once had a true moment of faith in Jesus and became Biblically saved, then we are still saved regardless what we later believe (or don't believe) about various issues, including eternal security. They cannot logically say we are unsaved because we oppose eternal security, for their own theology won't allow it.
That same concept can be carried over to those who convert over to Jehovah's Witnesses, Mormonism or Catholicism. The eternal security proponents cannot logically say the people in such groups are unsaved because of their present heretical beliefs, for if such ever had a true moment of faith in Jesus before becoming a Mormon, Catholic, Jehovah's Witness, etc., then they are still saved. For them to say otherwise is to logically deny their own eternal security doctrine.