We are so use to reacting in a certain way when faced with stressful situations that those reactions get stored in the body in the form of memories (body has memories too), and we tend to repeat these patterns over and over through out lives which results in conditioning of our mind, emotion and body patterns. Mediation helps us break this pattern because now you learn to take a pause, observe and then respond. Gradually this will create a new way of living for you breaking the old patterns, this in turn will raise your vibrations because you are no longer in a reactive cycle crafted my your conditioning and because the monkey chatter that goes on in your mind gradually decreases as you become more and more aware of the present. You start living in the present which expands your consciousness gradually and you start to align within yourself in terms of your mind body and soul. And this is how our expansion starts.