The Orthodox Church teaches that all people are created by God in His image and are related to each other, and that Christ's commandments about love for one's neighbor have no boundaries. That is why St. Theodosius of the Caves said: "If you see someone naked or hungry, or in trouble, whether he be a Jew or a Muslim, be merciful to everyone, deliver him from trouble as much as you can, and you will not be deprived of God's reward, for God Himself in the present age pours out His mercies not only on Christians, but also on the infidels" (Testament).

At the same time, it must be understood that the respect, mercy and personal affection that an Orthodox Christian shows to a person of a different faith does not mean sympathy or agreement with the convictions that this person shares. There are insurmountable doctrinal differences between Orthodoxy and Islam on a number of dogmas.

However, as St. Nicholas the Mystic pointed out in a letter to the Caliph al-Muqtadir, "because we are divided by the way of life, manners and objects of worship, of course, we should not be disposed to hostility and deprive ourselves of communion" (1 letter).

Many Christian saints had acquaintances and conversations about faith with Muslims, for example, St. John of Damascus, St. Constantine the Philosopher, St. Theodore of Edessa, St. Samon of Gaza, St. Gregory Palamas. Following their example, the Orthodox Church welcomes dialogue with Muslims aimed at clarifying and witnessing the faith in the face of people of other faiths, with the aim of eliminating errors and misunderstandings, in the words of St. Basil the Great: "If there is any mutual affinity between the teachings, then the knowledge of them will be useful to us. If there is no such affinity, then to study the difference of the teachings, comparing them with each other, will serve a great deal to confirm the best teaching" (Discourse 22).

Although this book is written by a Christian, I have tried to present the Muslim teachings as adequately as possible, based on my ten years of experience in studying them. Over the years, I have had the opportunity to be a participant and witness of many polemical conversations, and I have managed to make sure that the main problem in dialogue is ignorance and misunderstanding of the faith of the interlocutor.

To overcome this problem, this book was written, in which the most important points of the doctrine of Orthodox Christianity and Islam are compared. Namely, the doctrine of God and the related doctrine of predestination, the concept of sin, then the chapters on Jesus Christ and Muhammad, then on the Bible and the Koran, and, finally, the doctrine of life after death.

Each chapter of the book is divided into two parts: the first gives the Muslim teaching on this point, and the second - the Christian one. The tenets of religion are set forth according to its own sources – in the case of Islam, these are the Koran and Sunnah (sacred tradition), early biographies of Muhammad, works of ancient and modern theologians, and in the case of Christianity, the Bible and the Holy Tradition of the Orthodox Church, expressed in the decisions of Councils and in the writings of the Holy Fathers.

For greater clarity, the names of biblical persons mentioned in the Qur'an are given, as a rule, not in the Arabic transcription, but in the traditional Christian spelling.

The chapter "Jesus Christ" (in the part concerning Orthodox teaching) was written in co-authorship with the priest Daniel Sysoev, and the chapter "Holy Scripture" was co-authored with Alexander Lyulka. To both of them, I express my deep gratitude for their invaluable advice and help in writing this book.

Over the past decades, two paths have taken shape in the sphere of interreligious dialogue: either polite politically correct verbiage, or an honest conversation on the point.

This book is for those who prefer an honest conversation.

And it contains answers to the questions that Muslims usually ask Christians: about faith in the Trinity and the Incarnation, about the Bible, about original sin and the death of Jesus Christ, and also about why Christians do not recognize Muhammad as a prophet and the Koran as the Word of God.

I hope that this modest work will serve the cause of mutual understanding between Christians and Muslims.