Do you mortify; do you make it your daily work; be always at it whilst you live; cease not a day from this work; be killing sin or it will be killing you.Of the Mortification of Sin in Believers Chapter 2
That is why the unregenerate person cannot understand the urgency of the gospel message: until they see the depth of their sin and the holiness of God, they find no reason to seek remedy for their condition.
When I turn to the map of the world I must say the same thing. It matters not what quarter I examine: I find men's hearts are everywhere the same, and everywhere wicked. Sin is the family disease of all the children of Adam.Old Paths, Ch 7
At the heart of all sin is a lie. The lie says to all of us in our sin, "The act you are now doing, the desire or attitude you are now feeling is not very bad because there are much worse things, not very bad because everyone else experiences the same things, not very bad because you can't help it, not very bad because there is no God, or, if that won't work, God knows you are but frail and weak and he will tolerate and pity your sin." There are a thousand distortions of the truth which sin brings with it into the human heart, so that Jeremiah cries out, "The heart is deceitful above all things and desperately corrupt; who can understand it?" (17:9).
You can never part with sin soon enough; it is a cursed inmate, that will surely bring mischief upon the soul that harbours it. It will set its own dwelling on fire.Works 7:147
The reading and contemplation of the Scriptures is enjoined upon men of all languages, therefore the translation of it into the native tongues is necessary. Since men speak different languages and are not all familiar with those two in which it was first written, it cannot be understood by them unless translated; it comes as the same thing to say nothing at all and to say what nobody can understand. But here it happens by the wonderful grace of God that the division of tongues (which formerly was the sign of a curse) becomes now the proof of a heavenly blessing. What was introduced to destroy Babel is now used to build up the mystical Zion.
It was not necessary for the apostles to write a catechism so as to deliver their doctrines professedly. It was enough for them to hand down to us those doctrines in accordance with which all symbolical books and catechisms might be constructed. If they did not formally write a catechism, they did materially leave us either in the gospels or in the epistles those things by which we can be clearly taught the principles of religion (katécheisthai).
If theology takes some things from other systems, it is not as an inferior from superiors, but as an superior from inferiors (as a mistress freely using her handmaids). Theology does not so much take from others, as presupposes certain previously known things upon which it builds revelation.
Institutes of Elenctic Theology
That God is the object of theology is evident both from the very name (theologias and theosebeias), and from Scripture which recognizes no other principal object.Institutes of Elenctic Theology
Thus that all things are discussed in theology either because they deal with God himself or have a relation (schesin) to him as the first principle and ultimate end.Institutes of Elenctic Theology
But the divine dayspring from on high is adored, Christ the Lord, who is our sun and shield; the sun of every blessing, asserting the glory of religion; the shield of the most safe protection, affording an invincible and inexpugnable guard to liberty.
The fallen condition of all humankind in Adam is not the result of mere social conditioning but is such "by nature" (φύσει, physei)Ephesians, Evangelical Exegetical Commentary (Bellingham, WA: Lexham Press, 2015), 152.