While it was Martin Luther who drove the nails that began the Reformation, if there is one man who is most closely associated with Reformed Theology, it would be John Calvin (1509-1564).
As historian Mark Noll noted: “If Luther sounded the trumpet for reform, Calvin orchestrated the score by which the Reformation became a part of Western civilization.”
But who was John Calvin?
Here’s a brief biography of the Reformer
Calvin’s Early Life
Calvin was born to a staunch Roman Catholic family in 1509 – 26 years after Luther was born – and he was just 8 years old when Luther posted his 95 Theses.
And although he never met Luther personally, he benefited from his writing and admired him greatly. Calvin said of Luther, “God roused Luther and the others, who carried the torch ahead, in order to recover the way of salvation; and by whose service our churches were founded and established.”
Luther and Calvin did not agree on all matters theologically, but they shared many of the same convictions. Like Luther, John Calvin was pressured by his father to study law. However, the moment word reached him that his father had passed away, Calvin switched gears and pursued a study of the classics.
However, Calvin was forced to flee from his homeland for his own safety. In November 1533, the rector of the University of Paris, a friend of Calvin’s named Nicolas Cop, preached an opening address for the winter semester. It was a plea for reformation and a return to the teachings of the New Testament. This smelled too much like Luther for those in authority to tolerate, and Cop was forced to flee.
Calvin, believed to have collaborated with Cop in preparing the sermon, was marked out as a follower of Luther’s. He sought refuge in Basel, Switzerland when deadly persecution arose against Protestant Christians in France.
While there, Calvin published the first edition of his most famous work, The Institutes of the Christian Religion. He was just 27 years old. This was 1536, the same year that William Tyndale was martyred in England. The Institutes would be revised and expanded a number of times over the years, and would serve as Calvin’s magnum opus.
A Detour To Geneva
That same year, Calvin made plans to go to Strasbourg to live a quiet life as a scholar, hoping to help the Reformation along by his writing.
However, war had broken out between Francis I and Charles the 5th (the same Charles the 5th that presided over the Diet of Worms a decade earlier), and so Calvin decided to make a detour in Geneva, Switzerland. It was only supposed to be for the night.
While in Geneva, a Reformer by the name of William Farel recognized Calvin, the now-famous author of The Institutes. Farel was the first reformer of Geneva, the one who fought to have the city become officially Protestant in May of 1536. But he needed help. A lot of help.
Farel asked Calvin to remain in Geneva to be his co-laborer in the work ahead. Calvin declined. Farel pleaded, and eventually took to praying an ‘imprecatory prayer,’ or a prayer of cursing, on Calvin’s studies if he were to go on to Strasbourg.
Calvin was so shook by this, he later said “I felt as if God from heaven had laid his mighty hand upon me to stop me in my course – and I was so stricken with terror that I did not continue my journey.”
The young theologian decided to stay, and Farel and Calvin set to work on Reforming the people of Geneva. Together, they tried to implement Reforms in a city that was known for its flagrant sin. Things deteriorated quickly.
One night in April, 1538 more than sixty musket blasts shot off in front of Calvin’s home late one night in an effort to scare him away. The pair ran afoul of the populace and the City Council when they prevented people from participating in communion while living in open sin. They were both banished from Geneva.
Calvin Goes To Strasbourg
Calvin was relieved. He would finally get to live in peaceful study in Strasbourg. Or so he thought. You see, another Reformer by the name of Martin Bucer found out that Calvin’s schedule had just cleared up.
Word must have gotten around about the success of Farel’s imprecatory prayer tactic, because Bucer told Calvin that he would be a modern-day Jonah if he did not use his God-given ability to teach and pastor.
“that most excellent servant of Christ, Martin Bucer, employing a similar kind of remonstrance and protestation as that to which Farel had recourse, before, drew me back to a new station. Alarmed by the example of Jonah which he set before me, I still continued in the work of teaching”
And so, Calvin spent three years pastoring 500 of his fellow French religious refugees in Strasbourg. He also got married, wrote his commentary on Romans, and revised his Institutes.
Calvin Returns to Geneva
The City Council of Geneva did not get along quite as well in Calvin’s absence. Cardinal Sadoleto was urging the Genevan church to return to Roman Catholicism, and they desperately needed someone to respond. If only they knew a brilliant Protestant theologian…After much pleading and resistance, Calvin agreed (you can read his response in A Reformation Debate).
In 1541 John Calvin returned to Geneva. He would minister there for the rest of his life. He taught and modeled that Scripture is to be the authority for every part of ministry.
Calvin’s view of the pastor’s job was this:
“Let the pastors boldly dare all things by the Word of God, of which they are constituted administrators. Let them constrain all the power, glory, and excellence of the world to give place to and to obey the divine majesty of the Word. Let them enjoin everyone by it, from the highest to the lowest. Let them edify the body of Christ. Let them devastate Satan’s reign.
Let them pasture the sheep, keel the wolves, instruct and exhort the rebellious. Let them bind and loose, thunder and lightning, if necessary, but let them do all according to the Word of God.” 
Calvin’s Pastoral Ministry
Calvin dedicated himself to preaching and teaching the Word of God. He preached over 4,000 sermons (though all but about 1500 were thrown away when a librarian needed to clear up some shelf space!).
He preached without notes, and he preached expositionally – that is, he preached sequentially through books of the Bible. In fact, when he first returned to the pulpit in Geneva after being banished, his sermon picked up at the very next verse from which he had left off three years prior!
In addition to preaching, he wrote many commentaries on Scripture, volumes upon volumes of pastoral and theological works, and set up a school to train pastors. Many of his students had fled from their homeland due to persecution and intended to return. They often joked that their diploma served a dual purpose as their death certificate – and for a great number of them who were put to death for their Protestant views this proved to be the case.
Calvin’s ministry would have a major impact on the city of Geneva, on the continuing success of the Protestant Reformation, and on the history of the church. When John Knox, the great Scottish Reformer, visited Geneva in 1554 he said that the city was “the most perfect school of Christ that ever was in the earth since the days of the apostles.” 
Knox was among those who sought refuge in Calvin’s Geneva and he, Calvin, Miles Coverdale, and others set to work on a translation of Scripture. The Geneva Bible, as it came to be called, was the first Bible with chapter and verse numbers and it was the first with study notes in the margins.
It was the Bible of John Bunyan and William Shakespeare; the Bible of the Puritans and the Pilgrims; even after the publication of the KJV, it remained the most popular English version for another 50 years.
Calvin’s Constant Trials
Despite all of these apparent successes, Calvin endured great difficulties during the ministry.
All of his children died in infancy. His wife, though she survived the plague when it initially ravaged Geneva, died after a lengthy illness in 1549. He faced constant opposition as a pastor. He was accosted in the street. People would attend church services and intentionally cough so loudly they would drown out his preaching; some threatened to drag him out and throw him in the river; others fired guns outside the church; men would set their dogs after him, and some even threatened his life.
On top of these external stresses, Calvin had a great deal of physical ailments: Severe pain, difficulty breathing, headaches, severe weight loss. Even years before his death he was described by some as a skeleton covered with skin.
Calvin’s Tireless Work
Despite these hardships, Calvin would not slow down his pace or reduce his ministry workload. When confronted about the need for rest, Calvin commented “What? Would you have the Lord find me idle when he comes?”
A Geneva resident during that time described Calvin’s workload:
Calvin for his part did not spare himself at all, working far beyond what his power and regard for his health could stand. He preached commonly every day for one week in two [and twice on every Sunday, or a total of about ten times every 2 weeks]. Every week he lectured three times in theology.
Every Friday at the Bible Study what he added after the leader had made his declaration was almost a lecture. He never failed in visiting the sick, in private warning and counsel, and the rest of the numberless matters arising out of the ordinary exercise of his ministry.
But besides these ordinary tasks, he had great care for believers in France, both in teaching them and exhorting and counseling them and consoling them by letters when they were being persecuted, and also in interceding for them.
Yet all that did not prevent him from going on working at his special study and composing many splendid and very useful books.
It was inevitable that Calvin’s many ailments would finally catch up with him. He wrote to his doctors, “At present all of these ailments, as it were, muster in troops against me.” 
And yet, even up to 8 days before his death Calvin was still writing and teaching! He was often carried to church in a chair in order to preach, because he was too weak to walk. On his deathbed he completed his commentary on the Old Testament book of Joshua.
By his own words, he counted his ministry as more valuable than his life. Why? Why did Calvin work so diligently? Why did he expend his life to the teaching of Scripture even in the face of so much difficulty and opposition?
Because, like Luther and Tyndale and a number of others, John Calvin was devoted to the truth of Scripture. His heart, too, was held captive to the Word of God.
On April 25, 1564, Calvin dictated the following words:
I render thanks to God, not only because he has had compassion on me, His poor creature, to draw me out of the abyss of idolatry in which I was plunged, in order to bring me to the light of His gospel and make me a partaker of the doctrine of salvation, of which I was altogether unworthy, and continuing His mercy He has supported me amid so many sins and short-comings, which were such that I well deserved to be rejected by Him a hundred thousand times—but what is more, He has so far extended His mercy towards me as to make use of me and of my labour, to convey and announce the truth of His gospel.
John Calvin, whose tireless ministry revealed that his heart was held captive to the Word of God, passed away on May 27, 1564 – just two weeks prior to his 55th birthday. At his request, he was buried in an unmarked grave at an undisclosed location in Geneva.
Whether or not one subscribes to the doctrinal system that came to bear his name, John Calvin’s legacy continues to this day. Generations of believers have benefited from the fruit of his diligent labor to preach and teach the Word of God.
Institutes of the Christian Religion
Here in a convenient one-volume edition is John Calvin’s magnum opus. Written as an introduction to the Christian life, the Institutes remains the best articulation of Reformation principles and is a marvelous introduction to biblical Christianity.
 Michael Horton, Calvin on the Christian Life: Glorifying and Enjoying God Forever, 40.
 From the preface of Calvin’s commentary on the Psalms.
 Lawson, The Expository Genius of John Calvin, 29.
 Keith A. Mathison, The Shape of Sola Scriptura, 103.
 John Piper, “John Calvin: Theologian for the Ages.”
 Timothy George, John Calvin and the Church: A Prism of Reform.
 Steve Lawson, “John Calvin: Theologian for the Ages.”
Thank you Clayton for writing this article, GREAT HELP!