The whole concept of Sufism is to feel one - be one - with nature, with the universe. They develop this feeling of oneness through certain physiological movements which are called Sufi dance. It is a practice of movements which are spontaneous, movements which open up the creative aspects of consciousness.
They believe that the whole universe is in constant motion and that all the planets, all the stars, all other celestial bodies move in a rhythm; they move in co-ordination with each other. In order to experience that movement they practise dance, and it is a very special dance. In it they try to become one with the movement of the celestial bodies, with the vibration of the universe. That philosophy is not really very far from the yogic philosophy, because they follow the basic principle that man should attune himself with the movement, with the vibration of nature, of the universe.
If you read the mantra shastras which contain the science of mantra, they say the same thing- that the cause of the universe is sound. If you read the ancient Indian scriptures, they talk about hiranyagarbha, the cosmic egg which split open. When it split open, creation came into being. Scientists today use a similar principle or theory to explain creation - the 'big bang' theory: first there was a concentrated energy, then it cracked, it split, it exploded.
Sufis and the mantra yoga philosophy both believe that where there is movement there is a big probability of vibration; where there is vibration there is a big possibility of the existence of sound - whether audible and/or inaudible. Where there is sound, there is vibration, there is movement.
In Sufi meditations you become one with the movement of various manifestations of prakriti, nature. One form can be: while sitting, imagine yourself to be a tree and you experience the movement, the life - energy, the stability, the solidity of the tree. You imagine that you are the trunk, perfectly still and firm. You have so many layers of skin in concentric circles, they all begin with a point, one bindu, and from that point, that bindu, those circles come out and that gives the shape to the tree. When you throw a pebble in the water you see ripples coming out. By throwing that pebble in the water you create a motion, you create a shape in the form of concentric circles. Imagine that you are that. Then again experience yourself to be the branches of a tree - some long, some short, some fat, some thin, some crooked, some straight; imagine that you are the leaves swaying in the wind.
In a nutshell, Sufism is becoming aware of the movement which is existing in each and everything and if we think about it from our normal perspective, with our common understanding, we see it is one of the highest forms of understanding purusha and prakriti. It is not through rationalisation, not through intellect, but by becoming aware of the principle of motion in everything that true understanding comes and enlightenment dawns.
All their sayings are in the form of examples and parables, poems, little stories which convey the deep knowledge- and they allow that story to sink in so that you follow that conduct, those codes, disciplines, the way of living in a spontaneous way. It is not an enforced doctrine, it is a very spontaneous way of life lived from moment to moment.