While researching Matthew Henry over the past six months or so, I’ve discovered that his favorite Old Testament text was Isaiah 1:18: “Come now, and let us reason together,” says the Lord, “Though your sins are like scarlet, they shall be as white as snow; though they are red like crimson, they shall be as wool.”

It’s especially the first part of the verse, “Come now, and let us reason together,” that occurs again and again throughout his commentary and also repeatedly in his forty-four other publications. Writing as the age of reason took hold in Western Europe he was at pains to emphasize the reasonableness of God and of Christianity. In 1696 he began a series of sermons on the reasonableness of Christianity, beginning and ending the series with sermons on Isaiah 1:18.

In his commentary on the Isaiah 1:18 passage, Henry shows God’s reasonableness towards His people Israel in a number of ways. He says, here is “a demonstration, at the bar of right reason, of the equity of God’s proceedings with them,” a demonstration that should encourage us also today.

1. God did not simply reject them as hopeless because of their sinful record.

Though God had rejected their services as insufficient to atone for their sins while they persisted in them, yet he does not reject them as in a hopeless condition.

2. God came down to their level to reason with them.

The God of heaven condescends to reason the case with those that contradict him and find fault with his proceedings.

3. God requested evidence of sincere repentance and reformation before he discussed matters further with them.

“While your hands are full of blood I will have nothing to do with you, though you bring me a multitude of sacrifices; but if you wash, and make yourselves clean, you are welcome to draw nigh to me; come now, and let us talk the matter over.”

4. God did not merely criticize them but outlined a way of reconciliation.

Let them not say that God picked quarrels with them; no, he proposes a method of reconciliation.

 5. God insisted that no amount of service to God can cover up for unjust dealings with men.

As justice and charity will never atone for atheism and profaneness, so prayers and sacrifices will never atone for fraud and oppression; for righteousness towards men is as much a branch of pure religion as religion towards God is a branch of universal righteousness.

6. Despite their previous rebellion, they can be restored to God’s favor.

They could not in reason expect any more than, if they repented and reformed, they should be restored to God’s favor, notwithstanding their former provocations.

7. God required so little of them – just that they express willingness and desire to obey.

He does not say, “If you be perfectly obedient,” but, “If you be willingly so;” for, if there be a willing mind, it is accepted. 

8.  How much is promised in return – the pardon of all sins and the enjoyment of all the happiness they could want. 

That is very great which is promised hereupon. [1.] That all their sins should be pardoned to them…[2.] That they should have all the happiness and comfort they could desire.

9. If they refused such an offer and continued in their disobedience they would suffer the just punishment for that.

They could not in reason expect any other than that, if they continued obstinate in their disobedience, they should be abandoned to ruin, and the sentence of the law should be executed upon them.

Henry said these truths about God’s reasonableness were not just applicable to Old Testament Israel but also to the New Testament church.

The case needs only to be stated (as it is here very fairly) and it will determine itself. God shows here upon what terms they stood and then leaves it to them to judge whether these terms are not fair and reasonable.

And now life and death, good and evil, are thus set before you. Come, and let us reason together. What have you to object against the equity of this, or against complying with God’s terms?”

Religion has reason on its side; there is all the reason in the world why we should do as God would have us do.

Interestingly, Henry’s favorite New Testament verse, at least judged by frequency of occurrence, was: “But sanctify the Lord God in your hearts, and always be ready to give a defense to everyone who asks you a reason for the hope that is in you, with meekness and fear” (1 Pet. 3:15). In other words, it’s not just that God is reasonable and reasons with us, but He also calls us to be reasonable and to reason with others in our Gospel witness.