I don't know...I am not sure I can recommend this book for Christians. I have come back to my Christian faith two years ago after leaving it in my early 20s, having grown up Catholic. Since 2006, I have meditated: first, Vipassana and then I had an experience at a retreat which led me back to Christianity, where I have practiced contemplative prayer ever since. Both vipassana and contemplative prayer are similar, but they also have important differences. In Sadhana, Anthony writes about "emptiness" and "darkness" as good things to achieve, and he recommends to "empty the mind of all content". But in contemplative prayer, and from my limited experience, a Christian doesn't empty the mind or find "emptiness" but the mind becomes full, with a lightness and a "suchness". Never a trance, always more of being in the present moment, watching thoughts. Some of his awareness exercises are definitely helpful, but not his language. And I would worry people would not learn the wonderful benefits of abiding with Christ, but would simply find some "peacefulness", as the author promotes, if doing his exercises. While peacefulness is wonderful, without God it is not. I googled him, and there is a vatican document where Cardinal Joseph Ratzinger (Pope Benedict 16) warns against studying Anthony de Mello's work.
This is the document:
NOTIFICATION
CONCERNING THE WRITINGS OF
FATHER ANTHONY DE MELLO, SJ
The Indian Jesuit priest, Father Anthony de Mello (1931-1987) is well known due to his numerous publications which, translated into various languages, have been widely circulated in many countries of the world, though not all of these texts were authorized by him for publication. His works, which almost always take the form of brief stories, contain some valid elements of oriental wisdom. These can be helpful in achieving self-mastery, in breaking the bonds and feelings that keep us from being free, and in approaching with serenity the various vicissitudes of life. Especially in his early writings, Father de Mello, while revealing the influence of Buddhist and Taoist spiritual currents, remained within the lines of Christian spirituality. In these books, he treats the different kinds of prayer: petition, intercession and praise, as well as contemplation of the mysteries of the life of Christ, etc.
But already in certain passages in these early works and to a greater degree in his later publications, one notices a progressive distancing from the essential contents of the Christian faith. In place of the revelation which has come in the person of Jesus Christ, he substitutes an intuition of God without form or image, to the point of speaking of God as a pure void. To see God it is enough to look directly at the world. Nothing can be said about God; the only knowing is unknowing. To pose the question of his existence is already nonsense. This radical apophaticism leads even to a denial that the Bible contains valid statements about God. The words of Scripture are indications which serve only to lead a person to silence. In other passages, the judgment on sacred religious texts, not excluding the Bible, becomes even more severe: they are said to prevent people from following their own common sense and cause them to become obtuse and cruel. Religions, including Christianity, are one of the major obstacles to the discovery of truth. This truth, however, is never defined by the author in its precise contents. For him, to think that the God of one's own religion is the only one is simply fanaticism. "God" is considered as a cosmic reality, vague and omnipresent; the personal nature of God is ignored and in practice denied.
Father de Mello demonstrates an appreciation for Jesus, of whom he declares himself to be a "disciple." But he considers Jesus as a master alongside others. The only difference from other men is that Jesus is "awake" and fully free, while others are not. Jesus is not recognized as the Son of God, but simply as the one who teaches us that all people are children of God. In addition, the author's statements on the final destiny of man give rise to perplexity. At one point, he speaks of a "dissolving" into the impersonal God, as salt dissolves in water. On various occasions, the question of destiny after death is declared to be irrelevant; only the present life should be of interest. With respect to this life, since evil is simply ignorance, there are no objective rules of morality. Good and evil are simply mental evaluations imposed upon reality.
Consistent with what has been presented, one can understand how, according to the author, any belief or profession of faith whether in God or in Christ cannot but impede one's personal access to truth. The Church, making the word of God in Holy Scripture into an idol, has ended up banishing God from the temple. She has consequently lost the authority to teach in the name of Christ.
With the present Notification, in order to protect the good of the Christian faithful, this Congregation declares that the above-mentioned positions are incompatible with the Catholic faith and can cause grave harm.
The Sovereign Pontiff John Paul II, at the Audience granted to the undersigned Cardinal Prefect, approved the present Notification, adopted in the Ordinary Session of this Congregation, and ordered its publication.
Rome, from the offices of the Congregation for the Doctrine of the Faith, June 24, 1998, the Solemnity of the Birth of John the Baptist.