Of all tortures, except perhaps that of remorse, the worst is doubt about the truth of the religion in which a man has been brought up. Doubt also enfeebles a man, and prevents him from performing with any confidence the duties enjoined on him by his religion. It also deprives him of his hopes of an After-life and exposes him to all the temptations of the Devil. But the very existence of so many different religions in the world is permitted for a time by God in order to make the thoughtful man and the earnest truth-seeker inquire, "What proof have I that my religion is the truth?" If no one asked such a question, the heathen would never be truly converted to Islam or to Christianity. Hence it is clear that sincere examination of the foundations of one's faith and one's religion is a good thing, provided it be undertaken with humility and earnest desire to know God's will, and to do it. For those who cherish this desire in their hearts will assuredly pray continually to God Most Merciful, entreating Him to grant them light and guidance, in order that they may find the truth and walk as children of the light. If such a man finds his own religion true, then he has conquered doubt and put it to flight for ever, and can from the depth of a grateful heart thank God for His grace and guidance. Moreover, knowing the truth, he can teach other men the way of salvation. But should he find on examination that his own religion on the whole is not true, although doubtless it contains certain truths, then he has a chance of escaping from the error of his way and of finding the way that leads to God and to eternal life. In either case nothing but good can result from an honest inquiry into the proofs upon which our faith rests. The danger is lest men, instead of boldly facing their doubts and examining them in reliance upon God, should flee from them. A man who tries thus to escape from his doubts is always pursued by them, and often he falls a victim to them at last, and dies an infidel, having no hope and without God in the world.

But of the true seeker the proverb is true, "Whoso¹ seeketh a thing and striveth findeth, and whoso knocketh at a door and persevereth entereth."

Therefore we invite our Muslim brethren² to join us in an inquiry into the proofs upon which their religion is based, just as they have joined us in examining in the first two parts of this Treatise the foundations of Christianity. It is unnecessary to mention once more the criteria already laid down for testing all religions. As we have used them in examining Christianity, so we must employ them in testing Islam. But this we shall do inwardly, lest our expression of opinion should seem to anyone lacking in courtesy and love.

The Muslim Kalimah [or Creed] consists of two parts, of which the first is accepted by Jews and Christians as sincerely as by Muslims themselves: "There is no god but God" This has been already pointed out more than once in this Treatise. The proofs of the Existence and Unity of God are given in multitudes of books as well as in the whole of Creation, so that there is no need to discuss here what is admitted by us all. God Most High,—may He be honoured and glorified,—has demonstrated His Existence and His Unity by every blade of grass, by our reason and conscience, in the wonderful order and harmony of Nature, and in ten thousand different ways.

But what constitutes the subject of our present inquiry is, "What proof is there of the second clause of the Kalimah? How can it be shown that Muhammad is the Apostle of God?" Muslims adduce many proofs in support of their belief in his office as prophet and apostle and in his Divine Commission. The chief of these proofs are:

(1) That the Old Testament and the New both contain clear prophecies about him.
(2) That the language and the teaching of the