Eternally Secure
Can anything separate us from the love of God which is in Christ Jesus? "I am convinced that neither death nor life, neither angels nor demons, neither the present nor the future, nor any powers, neither height nor depth, nor anything else in all creation, will be able to separate us from the love of God that is in Christ Jesus our Lord." Rom 8: 38,39 Notice a couple of things here. Paul indicates that one's security in Christ is not a function of time. For he says there's nothing in the present or the future which will separate us from Christ. So if a person is saved at one point in time, and you were to make a time machine and travel into the future to visit that person, Paul indicates that you would find that person would still be saved.
Now there are those who would give the exception that we can separate ourselves. But this independence of time excludes that idea. And not only so, but note that he says, "nor anything else in all creation". Are you a part of the creation? If you are part of the creation then Paul is saying that you cannot separate yourselves from Christ. Furthermore, due to the nature of the regeneration, there will never be the desire to do so, let alone the ability or possibility to do so.
Thus it is as Jesus said, "Most assuredly, I say to you, he who hears My word and believes in Him who sent Me has everlasting life, and shall not come into judgment, but has passed from death into life." John 5:24 The heaven/hell judgement is a thing of the past for those born of God.