God is victorious over his enemies through the death, resurrection and ascension of Christ. In the death of Christ, by dealing with human sin and paying the penalty for sin, he has overpowered sin and, therefore, the power that sin might have over us. Once sin is dealt with, then the power of death is conquered because sin and death work together. Sin is kind of like the stinger that death has, and once it stings you with sin, once you sin, then you are subjected to death, and you belong to death. But if you break that stinger, as Jesus did on the cross, then death can no longer hold you. It's like a toothless viper, or a spider whose fangs have been broken off. And so, what follows after the death of Jesus is the resurrection of Jesus, which is the vindication of his right-standing with God and that sin has been conquered. And his ascension to God's right hand is described in the New Testament as the final sign that he is victorious over his enemies, not only sin and death, but the authorities, powers and dominions, as mentioned, say, in Ephesians 1; they are under his feet now, they're already conquered. Nevertheless, they still exist, and so, at the end of Ephesians, in chapter 6, we see that believers do spiritual warfare with them, but we battle with a team that's already lost, and we are just waiting for the final siren to sound, and then the game is over. We already know we're on the winning side.