It appears that John Wesley was what might be called a “hopeful inclusivist”. An inclusivist is one who believes that we are saved only through Jesus, however, it is possible to be saved through Jesus without explicit and/or complete knowledge of him. The following quotes from Wesley give insight to his leanings. Take special note of Sermon 106, On Faith.
[4-7-11 Post updated to include some additional quotes]
….I have no authority from the Word of God “to judge those that are without.” Nor do I conceive that any man living has a right to sentence all the heathen and Mahometan world to damnation. It is far better to leave them to him that made them, and who is “the Father of the spirits of all flesh;” who is the God of the Heathens as well as the Christians, and who hateth nothing that he hath made. Sermon 125: On Living Without God, point 14.
Heathens and Muslims:
It cannot be doubted, but this plea [lack of knowledge] will avail for millions of modern Heathens. Inasmuch as to them little is given, of them little will be required. As to the ancient Heathens, millions of them, likewise were savages. No more therefore will be expected of them, than the living up to the light they had. But many of them, especially in the civilized nations, we have great reason to hope, although they lived among Heathens, yet were quite of another spirit; being taught of God, by His inward voice, all the essentials of true religion. Yea, and so was that Mahometan, and Arabian, who, a century or two ago, wrote the Life of Hai Ebn Yokdan. The story seems to be feigned; but it contains all the principles of pure religion and undefiled. Sermon 106, On Faith, I 4.
Heathens, Muslims, Jews:
But with Heathens, Mahometans, and Jews we have at present nothing to do; only we may wish that their lives did not shame many of us that are called Christians. We have not much more to do with the members of the Church of Rome. But we cannot doubt, that many of them, like the excellent Archbishop of Cambray, still retain (notwithstanding many mistakes) that faith that worketh by love. Sermon 106, On Faith, II 3.
It is not so easy to pass any judgment concerning the faith of our modern Jews. It is plain, “the veil is still upon their hearts” when Moses and the Prophets are read. The god of this world still hardens their hearts, and still blinds their eyes, “lest at any time the light of the glorious gospel” should break in upon them. So that we may say of this people, as the Holy Ghost said to their forefathers, “The heart of this people is waxed gross, and their ears are dull of hearing, and their eyes they have closed ; lest they should see with their eyes, and hear with their ears, and understand with their hearts, and should be converted, and I should heal them.” (Acts 28:27.) Yet it is not our part to pass sentence upon them, but to leave them to their own Master. Sermon 106, On Faith, I 6.
Heathens Who have Never Heard of Christ:
But one considerable difficulty still remains: There are very many heathen nations in the world that have no intercourse, either by trade or any other means, with Christians of any kind. Such are the inhabitants of the numerous islands in the South Sea, and probably in all large branches of the ocean. Now, what shall be done for these poor outcasts of men “How shall they believe,” saith the Apostle, “in Him of whom they have not heard And how shall they hear without a preacher” You may add, “And how shall they preach, unless they be sent” Yea, but is not God able to send them Cannot he raise them up, as it were, out of the stones And can he ever want means of sending them No: Were there no other means, he can “take them by his Spirit,” as he did Ezekiel. (Ezek. 3:12,) or by his angel, as he did Philip, (Acts 8,) and set them down wheresoever it pleaseth him. Yea, he can find out a thousand ways to foolish man unknown. And he surely will: For heaven and earth may pass away; but his word shall not pass away: He will give his Son “the uttermost part of the earth for his possession.” Sermon 63, The General Spread of the Gospel, 24.
Indians (from India), Pakistanis, Pacific Islanders:
We cannot account for his present dealings with the inhabitants of the earth. We know, “the Lord is loving unto every man, and his mercy is over all his works.” But we know not how to reconcile this with the present dispensations of his providence. At this day, is not almost every part of the earth full of darkness and cruel habitations In what a condition, in particular, is the large and populous empire of Indostan! How many hundred thousands of the poor, quiet people, have been destroyed, and their carcases left as the dung of the earth! in what a condition (though they have no English ruffians there) are the numberless islands in the Pacific Ocean! How little is their state above that of wolves and bears! And who careth either for their souls or their bodies But does not the Father of men care for them O mystery of providence! Sermon 69 – The Imperfection Of Human Knowledge. II 4
Those with Distorted Ideas of who Christ is:
Perhaps there may be some well-meaning persons who carry this farther still; who aver, that whatever change is wrought in men, whether in their hearts or lives, yet if they have not clear views of those capital doctrines, the fall of man, justification by faith, and of the atonement made by the death of Christ, and of his righteousness transferred to them, they can have no benefit from his death. I dare in no wise affirm this. Indeed I do not believe it. I believe the merciful God regards the lives and tempers of men more than their ideas. I believe he respects the goodness of the heart rather than the clearness of the head; and that if the heart of a man be filled (by the grace of God, and the power of his Spirit) with the humble, gentle, patient love of God and man, God will not cast him into everlasting fire prepared for the devil and his angels because his ideas are not clear, or because his conceptions are confused. Without holiness, I own, “no man shall see the Lord;” but I dare not add, “or clear ideas.” Sermon 125: On Living Without God, 15.
…the faith of the Roman Catholics, in general, seems to be above that of the ancient Jews. If most of these are volunteers in faith, believing more than God has revealed, it cannot be denied that they believe all which God has revealed, as necessary to salvation. In this we rejoice on their behalf… Sermon 106, On Faith, I 7