He has appeared once for all at the end of the age to remove sin by the sacrifice of himself. And just as it is appointed for mortals to die once, and after that the judgment, so Christ, having been offered once to bear the sins of many, will appear a second time, not to deal with sin, but to save those who are eagerly waiting for him. Heb. 9:26-28, NRSV.
Here is a passage that finds echoes in many places in the New Testament. The book of Hebrews tells us that Christ accomplished His sacrificial work when He died once for all on the cross. While that never needs to be repeated, by itself it leaves people only "half saved." He has yet to "appear a second time, not to deal [again] with sin, but to save those who are eagerly waiting for him."
Wait a minute! Aren't Christians already saved? Doesn't Ephesians 2:8 plainly teach through its use of the past tense that believers "have been saved" (NKJV) by grace through faith?
Those things are definitely true. So, we must ask, if Jesus has already redeemed Christians, how come Hebrews says that Jesus will return "to save those who are eagerly waiting for him"? How can they be saved but not yet saved? Before answering, we should realize that Paul takes up the topic in Romans 13, in which he appeals for Christians "to wake from sleep. For salvation is nearer to us now than when we first believed" (verse 11, RSV).
Part of the answer to the half-saved dilemma is that Romans speak of salvation from three different perspectives. One of them, justification, is past for believers. Another, glorification, is future. And the third, sanctification, is a present reality. Thus Christian living takes place between two great events. The first being justification, when believers gave their hearts to Christ. The second is His return at the end of the age.
And with that phrase, "end of the age," we hit upon the two great events that encompass all the New Testament era. The first is the beginning of the kingdom of God, which Jesus asserted He had inaugurated when He began His earthly ministry (Matt. 4:17). The second is the consummation of the kingdom, when Christ comes again.
That thought takes us to Romans 8:23, in which the apostle states that Christians "have the first fruits of the Spirit," but that they "groan inwardly as [they] wait for adoption as sons" and "the redemption of [their] bodies" (RSV).
The plain fact is that as believers we are half saved and half redeemed. The fullness of that salvation hope will not come until Jesus returns at the end of the age and gives us new bodies to go with our new hearts and wills.