Knowing, my beloved Marcianus, your desire to walk in godliness, which alone leads man to life eternal, I rejoice with you and make my prayer that you may preserve your faith entire and so be pleasing to God who made you. Would that it were possible for us to be always together, to help each other and to lighten the labor of our earthly life by continual discourse together on the things that profit. But, since at this present time we are parted from one another in the body, yet according to our power we will not fail to speak with you a little by writing, and to show forth in brief the preaching of the truth for the confirmation of your faith. We send you as it were a manual of essentials, that by little you may attain to much, learning in short space all the members of the body of the truth, and receiving in brief the demonstration of the things of God. So shall it be fruitful to your own salvation, and you shall put to shame all who inculcate falsehood, and bring with all confidence our sound and pure teaching to everyone who desires to understand it. For one is the way leading upwards for all who see, lightened with heavenly light: but many and dark and contrary are the ways of them that see not. This way leads to the kingdom of heaven, uniting man to God: but those ways bring down to death, separating man from God. Wherefore it is needful for you and for all who care for their own salvation to make your course unswerving, firm and sure by means of faith, that you falter not, nor be retarded and detained in material desires, nor turn aside and wander from the right.
Now, since man is a living being compounded of soul and flesh, he must needs exist by both of these: and, whereas from both of them offences come, purity of the flesh is the restraining abstinence from all shameful things and all unrighteous deeds, and purity of the soul is the keeping faith towards God entire, neither adding thereto nor diminishing therefrom. For godliness is obscured and dulled by the soiling and the staining of the flesh, and is broken and polluted and no more entire, if falsehood enter into the soul: but it will keep itself in its beauty and its measure, when truth is constant in the soul and purity in the flesh. For what profit is it to know the truth in words, and to pollute the flesh and perform the works of evil? Or what profit can purity of the flesh bring, if truth be not in the soul? For these rejoice with one another, and are united and allied to bring man face to face with God. Wherefore the Holy Spirit says by David:
Blessed is the man who hath not walked in the counsel of the ungodly: that is, the counsel of the nations which know not God: for those are ungodly who worship not the God that truly is. And therefore the Word says to Moses:
I am He that is; but they that worship not the God that is, these are the ungodly. And hath not stood in the way of sinners: but sinners are those who have the knowledge of God and keep not His commandments; that is, disdainful scorners. And hath not sat in the seat of the pestilential: now the pestilential are those who by wicked and perverse doctrines corrupt not themselves only, but others also. For the seat is a symbol of teaching. Such then are all heretics: they sit in the seats of the pestilential, and those are corrupted who receive the venom of their doctrine.