"He would bend over the pulpit," writes one who heard him before and after the change, "and press us to take the gift, as if he held it that moment in his hand and would not be satisfied until every one of us had got possession of it. And often after the sermon was over and the psalm sung, and he rose to give the blessing, he would break out afresh with some new entreaty, unwilling to let us go until he had made one more effort to persuade us to accept it."

What brought about the change? The fire of love divine was lit by pain, sickness, and death. First of all, a favorite uncle was found dead on his knees in the act of prayer. Chalmers was ill himself at the time and could not leave his bed but the news pierced his soul.

A long and severe illness followed. For four months he never left his room. For six months he never entered his pulpit. For a whole year his parish duties had to await his recovery. Then, when it was all over, the minister of Kilmany was a mere shadow of his former self. But he had been born again.

On March 17, 1810, he wrote in his Journal: "I have this day completed my thirtieth year and upon a review of the last fifteen years of my life, I am obliged to acknowledge that at least two-thirds of my time has been uselessly or idly spent. For by far the greater part of that time there has been total estrangement of my mind from religious principles." On August 21 he wrote: "I have conceived the idea of abandoning mathematics and expending my strength upon theological studies."

Regular and earnest study of the Bible was one of the first-fruits of his conversion. Before the crisis of his illness a neighbor remarked: "I find you are busy, sir, with one thing and another, but come what may, I never find you at your studies for the Sabbath." He replied: "O, one hour or two on the Saturday evening is enough for that." The same friend, observing the striking difference, remarked: "I never come in now sire, but I find you are at your Bible." "All too little, John, all too little," was his reply.

"I am much taken," he writes in his Journal in May 1811, "with Walker's observation that we are commanded to believe in the Son of God." Years afterwards he wrote to his brother, giving him a description of the change. He describes it as a great revolution in all his methods of thought. "I am now most thoroughly of the opinion that on the system, 'Do this and live' no peace can ever be found. It is believe on the Lord Jesus Christ and thou shalt be saved."

"Thus," says Hanna in his biography of Chalmers, "we can see him stepping from the treacherous ground of 'Do and live' to place his feet on the firm ground of 'Believe on the Lord Jesus Christ'." From that time he preached Christ as he had never preached Him before. His tongue was on fire. His half-empty church was filled. His sermons convicted soul after soul from sin and converted many to God. In the story of his crisis one is reminded of the early struggles of John Wesley.

Referring to his Kilmany years in a speech before the General Assembly in 1825 on the evils of combining ministerial office with professional duties, he said: "What, sir, are the objects of mathematic science? Magnitude and the properties of magnitude. But I had forgotten two magnitudes. I thought not of the littleness of time. I recklessly thought not of the greatness of eternity."