When Christ comes again they (Israel) shall see him and realize what a terrible mistake they have made as a chosen and elect people who have lived in unbelief all this time. They will see him and they will believe in him and God will take away their sins and they will be saved and they will mourn greatly as one who mourns for their only son. God is faithful and never forget what he has promised.
There is no promise from God to take away anyone's sins when Jesus comes again.
Forgiveness of sin is only
between his first and second comings.
The door is shut at the second coming, and no more can enter into salvation.
When Christ comes again, it will be to judge all mankind at the resurrection.
Peter says that "he must
remain in heaven until the time comes to restore everything" (Ac 3:21)
in the new heavens and new earth (2Pe 3:12-13) at the
end of time.
There is no more time, only resurrection, judgment and eternity, when Christ returns.
The letter to the
Hebrews states the same thing: there will be no appearing of Christ prior to his
coming in judgment, for
he appears but twice, once to atone and once to judge (Heb 7:28-29),
and not in between.
Just as men die once and then face judgment, so Christ appears once to die and once
to judge (2Th 1:7-10), at which time he will "bring salvation," the resurrection of our bodies
and completion of our adoption as sons.