The great argument of those who wanted to hinder the success of his[494] book was, that the author sufficiently shewed his inclination to Socinianism by his silence concerning the Trinity.  He opens his mind about this matter to his brother, September 25, 1638, “The book of the truth of the Christian Religion will live and flourish in spite of the envy of my enemies.  It was not proper for me to speak directly of the Trinity; and such as have heretofore brought their arguments to prove it from natural reason or the authority of Plato, have done more hurt than service to Christianity.”  The men who since Grotius’s time have acquired the greatest reputation in France by writing for the truth of the Christian Religion, such as Abbadie and Houteville, have followed his example, and avoided the discussion of questions which suppose the Divinity of the Scriptures.

Grotius had the satisfaction to find the Roman Catholics very well pleased with this treatise:  he writes to his brother[495], December 4, 1638, “My book of the Truth of the Christian Religion, which the Voetians look upon as Socinian, is so far from being Socinian here, that Roman-Catholic Monks are translating it into Persian, in order to make use of it in converting the Mahometans.  I have not attempted a direct proof of the Trinity (he writes to Gerard Vossius[496]) for I always remembered what I heard Junius your father-in-law say, who was a great man, that Du Plessis, and those who, like him, in their disputes with Atheists, Pagans, Jews, and Mahometans, endeavoured to establish the Trinity by arguments drawn from the light of nature, and by passages from Plato often misapplied, acted very imprudently, because they ought first to have convinced them of the truth of the Scriptures, which alone contain the doctrines which God has been pleased to reveal.”

A new edition of the book on the truth of the Christian Religion, with considerable additions, was published in 1639, which Grotius dedicated to his illustrious friend Jerom Bignon; and this great Magistrate, in returning him his thanks[497], gives the most favourable testimony to the work.  He says,[498] that tho’ the subject had already been well handled by several learned men, none of them had acquitted himself so well, nor discovered so great knowledge of the learned languages, and so much erudition, as Grotius.  He admires the order and conciseness of the work, and congratulates himself on living in Grotius’s time, and sharing in the friendship of so great a man.  Some time after the publication of this work, an Englishman[499] who had lived long in Turky, came to see Grotius, and acquaint him that he had translated it into the Turkish language, thinking no book more proper for instructing Christians who live in Turky, and converting the Mahometans.  He promised to use his endeavours to get it printed in the Turkish language in England.