The spiritually perfect Salaah (prayer)- (Imam Ghazali)

States Conducive to Perfecting The Life in Prayer (Inner Dimensions of Salaah)
These qualities can be expressed in many ways, but they are well summed up in six words, namely: awareness; understanding; reverence; awe; hope; shame.

Awareness

By conscious awareness we mean that state in which one’s mind and feelings are in no way distracted from what one is doing and saying. Perception is united with action and speech. Thoughts do not wander. When the mind remains attentive to what one is doing, when one is wholeheartedly involved, and when nothings makes one heedless, that is when one has achieved conscious awareness.

Understanding

Understanding the meaning of one’s words is something that goes beyond awareness, for one may be conscious of making an utterance, yet not be aware of the meaning of that utterance. What we mean by understanding, therefore, is an awareness that also includes comprehension of the meaning of one’s utterance. People differ in this respect, not sharing a common understanding of the Koran and the glorifications.
How many subtleties of meaning we have come to understand in the course of ritual prayer! Things that had never occurred to us before.
It is in this context that prayer becomes a deterrent to indecency and mischief, for the understanding it brings is a positive obstacle to vice.

Reverence

As for reverence, this is something beyond both awareness and understanding. A man may address his servant in full awareness of his speech, and understanding the meaning of his words, yet without reverence, for reverence is an additional element.

Awe

As for awe, it is over and above reverence. In fact, it represents a kind of fear that grows out of the latter. Without experiencing fear, one will not stand in awe. There is an ordinary fear of things we find repugnant, like scorpions or bad temper, but this is not called awe. What we call awe is the kind of fear we have of a mighty king. Awe is the kind of fear induced by a sense of majesty.

Hope

As for hope, this is unquestionably something else again. There are many who revere some king or other, and who are in awe of him or afraid of his power, yet do not hope to be rewarded by him. In our prayers, however, we must hope for the reward of Allah, High Exalted; just as we fear His punishment for our faults.

Shame

As for shame, it is something additional to all the rest, for it is based on the realization of one’s deficiencies and the apprehension of sin. It is quite possible to conceive of reverence, fear and hope, without this element of shame.

(From Imam Ghazali's Ihya ul uloom)