I have always found the little classic Beginning to Pray, by Metropolitan Anthony of Sourozh, to be one of the best introductions to prayer. I first discovered the book in college and used it in a small study group. It has never ceased to be relevant to my situation in life. His opening paragraphs are worth a short read (and more).

As we start learning to pray, I would like to make it clear that what I mean by ‘learning to pray’ is not an attempt to justify or explain this in a speculative way. Rather, I would like to point out what one should be aware of, and what one can do if one wishes to pray. As I am a beginner myself, I will assume that you are also beginners, and we will try to begin together. I am not speaking to anyone who aims at mystical prayer or higher states of perfection, because these things will teach themselves. When God breaks through to us or when we break through to God, in certain exceptional circumstances, either because things suddenly disclose themselves with a depth we have never before perceived or when or when we suddenly discover in ourselves a depth where prayer abides and out of which it can gush forth, there is no problem of prayer. When we are aware of God, we stand before Him, worship Him, speak to Him.

At the outset there is, then, one very important problem: the situation of one for whom God seems to be absent. This is what I would like to speak about now. Obviously I am not speaking of a real absence – God is never really absent – but of the sense of absence which we have. We stand before God and we shout into an empty sky, out of which there is no reply. We turn in all directions and He is not to be found. What ought we to think of this situation?

First of all, it is very important to remember that prayer is an encounter and a relationship, a relationship which is deep, and this relationship cannot be forced either on us or on God. The fact that God can make Himself present or can leave us with the sense of His absence is part of this live and real relationship. If we could mechanically draw Him into an encounter, force Him to meet us, simply because we have chosen this moment to meet Him, there would be no relationship and no encounter. We can do that with an image, with the imagination, or with the various idols we can put in front of us instead of God; we can do nothing of the sort with the living God, any more than we can do it with a living person. A relationship must begin and develop in mutual freedom. If you look at the relationship in terms of mutual relationship, you will see that God could complain about us a great deal more than we about Him. We complain that He does not make Himself present to us for the few minutes we reserve for Him, but what about the twenty-three and a half hours during which God may be knocking at our door and we answer ‘I am busy, I am sorry’ or when we do not answer at all because we do not even hear the knock at the door of our heart, of our minds, of our conscience, of our life. So there is a situation in which we have no right to complain of the absence of God, because we are a great deal more absent than He ever is.

My love of these opening paragraphs is the honesty with which our lives and God are approached. The rest of the book continues with this same honesty; as a result it is truly a classic on the life of prayer.