[prefixed to the last edition, revised by the author.]
In the first edition of this work, having not the least expectation of the success which God, in his boundless goodness, has been pleased to give it, I had, for the greater part, performed my task in a perfunctory manner (as is usual in trivial undertakings); but when I understood that it had been received, by almost all the pious with a favour which I had never dared to ask, far less to hope for, the more I was sincerely conscious that the reception was beyond my deserts, the greater I thought my ingratitude would be, if, to the very kind wishes which had been expressed towards me, and which seemed of their own accord to invite me to diligence, I did not endeavour to respond, at least according to my humble ability. This I attempted not only in the Second Edition, but in every subsequent one the work has received some improvement. But though I do not regret the labour previously expended, I never felt satisfied until the work was arranged in the order in which it now appears. Now I trust it will approve itself to the Judgment of all my readers. As a clear proof of the diligence with which I have laboured to perform this service to the Church of God, I may be permitted to mention, that last winter, when I thought I was dying of quartan ague, the more the disorder increased, the less I spared myself, in order that I might leave this book behind me, and thus make some return to the pious for their kind urgency. I could have wished to give it sooner, but it is soon enough if good enough. I shall think it has appeared in good time when I see it more productive of benefit than formerly to the Church of God. This is my only wish.
And truly it would fare ill with me if, not contented with the approbation of God alone, I were unable to despise the foolish and perverse censures of ignorant as well as the malicious and unjust censures of ungodly men. For although, by the blessing of God, my most ardent desire has been to advance his kingdoms and promote the public good,--although I feel perfectly conscious, and take God and his angels to witness, that ever since I began to discharge the office of teacher in the Church, my only object has been to do good to the Church, by maintaining the pure doctrine of godliness, yet I believe there never was a man more assailed, stung, and torn by calumny [as well by the declared enemies of the truth of God, as by many worthless persons who have crept into his Church--as well by monks who have brought forth their frocks from their cloisters to spread infection wherever they come, as by other miscreants not better than they  ]. After this letter to the reader was in the press, I had undoubted information that, at Augsburg, where the Imperial Diet was held, a rumour of my defection to the papacy was circulated, and entertained in the courts of the princes more readily than might have been expected.  This, forsooth, is the return made me by those who certainly are not unaware of numerous proofs of my constancy--proofs which, while they rebut the foul charge, ought to have defended me against it, with all humane and impartial judges. But the devil, with all his crew, is mistaken if he imagines that, by assailing me with vile falsehoods, he can either cool my zeal, or diminish my exertions. I trust that God, in his infinite goodness, will enable me to persevere with unruffled patience in the course of his holy vocation. Of this I give the pious reader a new proof in the present edition.
I may further observe, that my object in this work has been, so to prepare and train candidates for the sacred office, for the study of the sacred volume, that they may both have an easy introduction to it, and be able to prosecute it with unfaltering step; for, if I mistake not, I have given a summary of religion in all its parts, and digested it in an order which will make it easy for any one, who rightly comprehends it, to ascertain both what he ought chiefly to look for in Scripture, and also to what head he ought to refer whatever is contained in it. Having thus, as it were, paved the way, as it will be unnecessary, in any Commentaries on Scripture which I may afterwards publish, to enter into long discussions of doctrinal points, and enlarge on commonplaces, I will compress them into narrow compass. In this way much trouble and fatigue will be spared to the pious reader, provided he comes prepared with a knowledge of the present work as an indispensable prerequisite. The system here followed being set forth as in a mirror in all my Commentaries, I think it better to let it speak for itself than to give any verbal explanation of it.
Farewell, kind reader: if you derive any benefit from my labours, aid me with your prayers to our heavenly Father.
Geneva, 1st August 1559.
The zeal of those whose cause I undertook, Has swelled a short defence into a book.
"I profess to be one of those who, by profiting, write, and by writing profit."--Augustine, Epist. 7.
 The passage in brackets occurs only in the French original. The words are as follows: "Tant des ennemis manifestes de la vEritE de Dieu, que de beaucoup de canailles qui se sont fourrez en son Eglise: tant des Moines qui ont apportE leurs frocs hors de leurs cloistres pour infecter le lieu o? ils venoyent, que d'autres vilains qui ne valent pas mieux qu'eux."
 The words in the French are, "Avec trop grande facilitE; ce qui monstroit que beaucoup de mechans hypocrites, faisans profession de l'Evangile, eussent bien voulu qu'ainsi fust." With too great facility; showing that many wicked hypocrites, making profession of the gospel, would have been very glad it had been so.