Aldous Huxley in his book The Perennial Philosophy discusses four kinds of prayer common in all religions:
Adoration. Praising the deity.
Petition. Asking for favors.
Intersession. Asking favors for someone else.
Contemplation. Meditating on the nature of the deity—the Godhead, to use an old-fashioned term.
The Lords Prayer combines the first two forms in a pattern developed earlier by the Sumerians: Beginning by praising the deity (Hallowed be thy name. . . .), followed by a wish-list petition (Give us this day . . .), and ending with a short final praise (For thine is the Kingdom . . .).
The first three, adoration, petition, and intersession, are in the form of a conversation with a sentient being and are standard components of Christian prayers. The fourth, contemplation, is not a conversation, but a wordless union with the divine where conscious thought fades away, such as when peacefully walking in the woods or watching gentle ocean waves roll onto a beach. Not all consider this as valid prayer, seeing it only as self-indulgent pleasure.
Huxley considers contemplation not only valid, but the highest form, well above the other three. Prayer, he says, is the elevation of the mind to God, possible only by contemplation. Adoration is the activity by a loving individual, but whose expressed humbleness reinforces the sense of separateness from the deity. Contemplation involves, and even requires, a loss of self, and the less there is of self, the more there is of God.