We're going to simplify things a bit. WE are light. Light is created by vibration of energy. Each of us, however, vibrate at our own particular frequency, just as each of us has a different fingerprint. When we change anything in our life, even with the simplest thought, we change our vibrational frequency.
Negative emotions vibrate on a low frequency, and positive emotions vibrate on a higher frequency.
Think back to a time when you were depressed, for example. That is an example of a lower vibration brought on by negative emotions. Now think of a time when you received some really great news and were full of positive thoughts. That is an example of how positive emotions bring about a higher rate of vibration. If we choose to think positively, to have feelings of love, forgiveness, appreciation, happiness, and reverence, we will increase our vibrational frequency, which in turn, will bring us closer to the light of our soul.