Ahhhhh, I see what you are saying, and at least in a sense I agree. Yes, in Matthew 25, in Jesus's graphic portrayal of the final Judgment, he has two exchanges, first with those on His right, and then with those on His left:
Those on His right: They know they had a relationship with Christ; all those with true God-given faith do, but they even question themselves, in a way, asking Jesus, "Lord, when did we see you hungry and feed you, or thirsty and give you drink? And when did we see you a stranger and welcome you, or naked and clothe you? And when did we see you sick or in prison and visit you?" They are not denying that they had a personal relationship with Christ, but just not fully aware of it. And Jesus says He will answer them, "Truly, I say to you, as you did it to one of the least of these my brothers, you did it to me." So like, when did we do these good works? And Jesus will affirm the personal relationship ~ and the good works that they have done because of the relationship.
Those on His left: They will find out that they never had a personal relationship with Christ even though they might have thought they did; they will say, "Lord, when did we see You hungry or thirsty or a stranger or naked or sick or in prison, and did not minister to you?" In that question itself you can see their obliviousness; it's really a statement that, in effect, "We never saw you or knew you." And of course, Jesus will say to them, "as you did not do it to one of the least of these, you did not do it to me." Elsewhere He says He will say, "I never knew you." So He will finally and definitively say, there never was any personal relationship, and there were never any good works evidencing any kind of relationship.And these will be... sent away.
So, in a certain way, I agree: all will claim a personal relationship with Christ, either truly or falsely. Perhaps ~ perhaps ~ this is what you're saying. But I disagree with your statement on it's face ~ at face value, if this is what you're saying ~ that the final Judgment will not involve all but only some. All are in view here, and it is in keeping with Jesus's statement recorded by John in John 5:28-29, that "an hour is coming when all who are in the tombs will hear his voice and come out, those who have done good to the resurrection of life, and those who have done evil to the resurrection of judgment," and Paul's statement in Romans 2:6-8, that "He will render to each one according to his works: to those who by patience in well-doing seek for glory and honor and immortality, He will give eternal life; but for those who are self-seeking and do not obey the truth, but obey unrighteousness, there will be wrath and fury."
Grace and peace to you.