The period of time leading up to the end of the system of things, or state of affairs, dominated by Satan. It runs concurrently with Christ’s presence. Under the direction of Jesus, angels will “separate the wicked from among the righteous” and destroy them. (Mt 13:40-42, 49) Jesus’ disciples were interested in the timing of that “conclusion.” (Mt 24:3) Before his return to heaven, he promised his followers that he would be with them until that time.​—Mt 28:20.