There is the spiritual life in God. This is what relates us to the Infinite. You get everything in Supreme Soul, as He is Self-contained and Omnipresent. All your wants and desires are satisfied there. There is then the physical life. This it is that connects us with the universe around us. The thought-life connects the one with the other. It is this that plays between the two.
We have the power within us to open or close ourselves to the divine inflow exactly as we choose. This we have through the power of mind, through the operation of thought. If you are Rajasic (Passionate), you are far from God. You have shut yourself up from God. If you are Sattvic (Pure), you open yourself to the divine inflow.
The sacred River takes its origin in Mountains and runs perennially towards Sea. Similarly, thought-currents take their origin from the bed of Impressions in the mind, wherein are imbedded the latent subtle desires, and flow incessantly towards the objects both in waking state and dream. Even a railway engine is sent to the engine-shed for rest when the wheels become over-hot. But, this mysterious engine of mind goes on thinking without a moment’s rest. The expansion of this mind alone is union of thoughts; and, union of thoughts, through its power of differentiation, generates this universe.
A person without Self Knowledge has fickle minds with a great deal of fluctuation and myriads of thoughts. Their minds ever vacillate through thoughts. But, a person with complete Self Knowledge will be free from thoughts. They will be ever resting in their Soul Knowledge (Self Knowledge) which gives the highest satisfaction and Supreme Peace.
Mind – Its Mysteries and Control by Sri Swami Sivananda