Celsus goes on to say: “They must make their choice between two alternatives. If they refuse to render due service to the gods, and to respect those who are set over this service, let them not come to manhood, or marry wives, or have children, or indeed take any share in the affairs of life; but let them depart hence with all speed, and leave no posterity behind them, that such a race may become extinct from the face of the earth. Or, on the other hand, if they will take wives, and bring up children, and taste of the fruits of the earth, and partake of all the blessings of life, and bear its appointed sorrows (for nature herself has allotted sorrows to all men; for sorrows must exist, and earth is the only place for them), then must they discharge the duties of life until they are released from its bonds, and render due honour to those beings who control the affairs of this life, if they would not show themselves ungrateful to them.
For it would be unjust in them, after receiving the good things which they dispense, to pay them no tribute in return.” To this we reply, that there appears to us to be no good reason for our leaving this world, except when piety and virtue require it; as when, for example, those who are set as judges, and think that they have power over our lives, place before us the alternative either to live in violation of the commands of Jesus, or to die if we continue obedient to them. But God has allowed us to marry, because all are not fit for the higher, that is, the perfectly pure life; and God would have us to bring up all our children, and not to destroy any of the offspring given us by His providence.
And this does not conflict with our purpose not to obey the demons that are on the earth; for, “being armed with the whole armour of God, we stand” as athletes of piety against the race of demons that plot against us.
Source: Against Celsus (New Advent)