When you look into an abyss, the abyss also looks into you.
Eternal life and the invisible world are only to be sought in God. Only within Him do all spirits dwell. He is an abyss of individuality, the only infinite plenitude.
Whoever fights monsters should see to it that in the process he does not become a monster. And if you gaze long enough into an abyss, the abyss will gaze back into you.