The First Apology Of Justin by Justin Martyr
Chapter XI.--What kingdom Christians look for.
And when you hear that we look for a kingdom, you suppose, without making any inquiry, that we speak of a human kingdom; whereas we speak of that which is with God, as appears also from the confession of their faith made by those who are charged with being Christians, though they know that death is the punishment awarded to him who so confesses. For if we looked for a human kingdom, we should also deny our Christ, that we might not be slain; and we should strive to escape detection, that we might obtain what we expect. But since our thoughts are not fixed on the present, we are not concerned when men cut us off; since also death is a debt which must at all events be paid.