The Epistles of Ignatius

Am I not able to write to you of heavenly things? But I fear to do so, lest I should inflict injury on you who are but babes [in Christ]. Pardon me in this respect, lest, as not being able to receive [such doctrines], ye should be strangled by them. For even I, though I am bound [for Christ], yet am not on that account able to understand heavenly things, and the places of the angels, and their gatherings under their respective princes, things visible and invisible. Without reference to such abstruse subjects, I am still but a learner [in other respects]; for many things are wanting to us, that we come not short of God.