The knowledge of a thing leads to the knowledge of its opposite; for instance, if we know the right side we shall know the left; and if we know what is true, we shall easily know what is false. And, although truth is at constant war with falsehood, nevertheless, he that draws nigh to truth, will ever be victorious. Therefore, when different and contrary opinions prevail among men, that opinion may be held to be most probably true which is supported by the soundest reasoning. Now, as there exists much discord amongst men on matters of religion, and the arguments in favour of Christianity are much stronger than those that can be advanced in support of any other form of belief, Christianity must indubitably be the true religion. This is the point which we shall undertake in this Book to prove, first in general, and then in particular.
CHAPTER I.
NO RELIGION EXCEPT CHRISTIANITY CAN BE TRUE.
From what has just been said, it is evident, that Christianity is the only true religion. And if this be the case, and if there be no salvation except through the faith of Christ, all, save Christians, must be living in error.
Again, if a virtuous life be the end proposed by all religions, and if there be no better life than the Christian life, there can be no religion superior to Christianity. Any other religion must be either equal or inferior to it. If other religions be inferior to Christianity, Christianity must be the best; and we are bound to embrace it, and to reject all others as idle and superstitious. But if there be a religion equal to Christianity, it must be the same as Christianity. For, unless it propose to us the same end to be attained, and the same means for the attainment of that end, as Christianity professes, it cannot be called equal; it must be inferior to the Christian creed.
Furthermore, if we know a cause by its effects, and if Christian holiness be the perfection of human life; and, if we see no such effects produced by any other religion, Christianity must be true; the more so, as its effects are so quickly and so easily produced, and as its power appears so marvellously in the conversion of men. Therefore, there can be no danger of erring in rejecting all other creeds, and cleaving to the faith of Christ.
In order, however, to make what we say more clear, we will descend to particulars, and will discuss divers forms of religion. But, as it would be useless to attempt to discuss all the superstitions which have ever existed, we will reduce them to six, viz., heathen philosophy, astrology, idolatry, Judaism, heresy, and Mahometanism. In our analysis of these false religions, we will ignore the different opinions and divisions which have existed amongst philosophers, astrologers, idolaters, and heretics. We will examine their tenets from a general point of view.
CHAPTER II.
THE DEFECTIVE AND ERRONEOUS RELIGIONS TAUGHT BY HEATHEN PHILOSOPHERS.
We must preface our remarks by observing that the teaching of heathen philosophy, even where its leaders have not taught erroneous doctrine, is, in all that regards salvation, exceedingly poor and insufficient. Nor can we wonder at this, seeing that their only guide was the light of human reason. For, as the end to which we aspire must be the rule of all our operations, those who undertake to lead men to a virtuous way of living ought, at least, to know what is the true end of human life. Now, the heathen sages could have no such knowledge, because it exceeds the bounds of human reason, by which alone they were enlightened. But if they could not know the last end of man, still less could they know by what means he could attain his end. Therefore, all that they could teach about religion was necessarily imperfect, uncertain, or erroneous. What sane person, then, would abandon Christianity, for the tenets of heathen philosophy?