Angelic Rebellion & Human Rebellion Resulted In Christ's First Coming

The problem of angelic rebellion in heaven and the ruin of God's perfect creation on earth through the disobedience of Adam and Eve at satan's instigation required the inauguration of God's kingdom-rule through Christ's victory over sin, death and satan at the Cross and resurrection.

Christ's Second Coming Will Reverse Both Human & Angelic Rebellion For Eternity

The final victory over all the forces of evil, both human and satanic, however, cannot take place until Christ's return at the Second Coming and the final defeat of sin, death and satan at the Day of Judgement.

The full wonder of Jesus' death & resurrection becomes apparent when we realise how pivotal they are in God's overall plan of salvation.