He realized the truth of the proverb, "He that is surety for his friend shall smart." He became surety for some friends, and for this voluntarily gave up all that he had made to pay the debts of others. He says: "I never felt happier than when the burden was lifted, although it cost me fifty thousand dollars of fine real estate." He did not try to escape paying the debt. He had said by becoming surety for his friends that if they did not pay their debts he would, and this he did. He was not discouraged, but cheerfully resumed his business career and soon became prosperous again. In 1820 he was elected to Congress, and was re‑elected in 1822. At the height of a successful business career and at a time when he was rising rapidly in political affairs, much to the regret of his friends, he retired to private life. He says: "A sacred regard for domestic life moved me to take this course I had so long desired." It seems that in the providence of God he was being led into a different field of labor.

He was trained in the Baptist faith, and early in life received an impression that he ought to be a Christian. However, the affairs of life crowded upon him and he did not attach himself to the Baptist Church until he was thirty-three years of age. Mr. Campbell was publishing the Christian Baptist at that time. He became disturbed in his Baptist faith and determined to examine it in the light of the Bible. He says: "My eyes were opened and a new interest awakened in Christianity." He further adds: "I was convinced, won over, and contended with all my might in the private circle."

He soon began to preach the gospel. He thought that he should instruct, enlighten, and restore the Baptist Church, of which he was a member, to the New Testament order of work and worship. He was now forty-two years old, in the prime of his manhood. He was cool, courageous, and collected under the most trying circumstances. He never became excited, but moved about in a most stately way amid the most exciting scenes. He was unable to get the Baptist Church at Great Crossings to accept the New Testament as its only creed, so he resolved to establish a church on the Bible alone as containing the infallible rule of faith and practice. He succeeded in doing this. He gave up everything in order to preach the gospel. He lived in the county with Barton W. Stone. He soon joined Mr. Stone in editing the Christian Messenger, and he continued this work for three years, or until Stone moved to Illinois. He was a clear, forcible writer, and his editorials added much to the cause of Christ at that time.

There were two groups of religious people at that time. One group had been taught by B. W. Stone, and the other had been led to see the truth by Alexander Campbell. Those who had been taught by Stone were called "Christians," while those who had been taught by Mr. Campbell were called "Disciples." These two groups soon began to overlap in territory and in interest. They had started without any knowledge of each other; but as they both believed the same thing and practiced the same thing, they were united in faith and in the Lord, but did not recognize this union in their relation to each other. John T. Johnson was a great factor in 1833 in bringing together and getting each to recognize the unity, which already existed between the two groups. He says: "I was among the first, in cooperating with B. W. Stone, to suggest and bring about a union between the church of Christ and that large body of Baptists which had renounced all humanisms in religion." He was so impressed with the Bible teachings on unity that he made the theme of unity paramount in all of his preaching. He reasoned well, that he who does most to unite the followers of Jesus does most for the conversion of the world.

It has been said that of all the pioneers of the Restoration, John T. Johnson was the most devoted, zealous, self-sacrificing. He could well say, like Paul, to his fellow apostles, that he had labored more abundantly than they all. There were few States in the Union at that time in which he did not preach the gospel and establish churches. Most of the large cities at that time were visited by him, and nearly always a church was established before he left. He was a man of marked individuality. He was apparently a delicate man. His bearing was gentle, refined, and dignified. His address was pleasing, his enunciation clear and distinct, and his reasoning convincing. He spoke rapidly. He was calm, self-possessed, and his deep, earnest manner of tone, gesture, and expression of countenance aroused the human soul to action. The audience always listened with rapt attention to him. He labored incessantly as an evangelist for seventeen years and became known as "The Evangelist of Kentucky."

While Mr. Campbell was in Nashville, Tenn., preaching, John T. Johnson visited Nashville, and, with his usual zeal, at once began a series of meetings. Mr. Campbell and Mr. Johnson visited Murfreesboro and Clarksville, and churches were established in these towns. This was in 1854 or 1855. John T. Johnson then visited Hopkinsville, Ky., and delivered eight discourses there, then passed on north to Louisville, and then to Indianapolis, Ind.

While in a meeting at Lexington, Mo., in December, 1856, he fell sick of pneumonia, and passed away on the evening of December 24. Mr. Campbell said of him: "I presume no laborer in word and doctrine in the valley of the Mississippi has labored more ardently, more perseveringly, or more successfully than has Elder John T. Johnson, during the whole period of his public ministry. How many hundreds, if not thousands, of souls he has awakened from the stupor and deathlike sleep of sin and inducted into the kingdom of Jesus, the King eternal, immortal, and invisible, the living know not."

The venerable Walter Scott, upon hearing of his death, wrote in the Christian Age that the sadness of his death, "carries to the bosoms of the brethren and relatives of the deceased so great a burden of grief, of woe, of wailing, and tears, that any effort on our part to increase or intensify it by words would be equally indiscreet, unfeeling, and unavailing. The stroke has fallen on our hearts with the unexpectedness of a jet of lightning from a cloudless sky."

John T. Johnson was a plain and simple preacher of the gospel. He presented the facts, commands, and promises of the gospel in a simple way. He was well suited to present the gospel to a plain and simple people. He was direct in all that he said; he used no circumlocution in reaching the point; he attacked sin and error directly. It is said that he never attempted ornamentation in any speech that he ever made, that he was the most practical preacher in his day; he never quoted a line of poetry in any of his discourses. Like Paul, he was determined to know nothing while in the pulpit, "save Jesus Christ, and him crucified." The desire of his soul was to enlist soldiers in the army of the Lord and to make them feel that they must fight the good fight of faith. John T. Johnson did much for the cause of Christ, and many in the great day will have cause to rejoice because of his labors.