The resurrection of all people.  The one who dies in his sin without Christ is hopelessly and eternally lost, therefore has no further opportunity of hearing the Gospel or for repentance.  The one who dies in Christ has everlasting life spent in the presence of God.

Which also said, Ye men of Galilee, why stand ye gazing up into heaven? this same Jesus, which is taken up from you into heaven, shall so come in like manner as ye have seen him go into heaven.  (Acts 1:11)

For the Lord himself shall descend from heaven with a shout, with the voice of the archangel, and with the trump of God: and the dead in Christ shall rise first:

Then we which are alive and remain shall be caught up together with them in the clouds, to meet the Lord in the air: and so shall we ever be with the Lord.  (1 Thessalonians 4:16-17)