The capacity to be alone is the capacity to love. It may look paradoxical to you, but it is not. It is an existential truth: only those people who are capable of being alone are capable of love, of sharing, of going into the deepest core of the other person - without possessing the other, becoming dependant on the other or addicted to the other. They allow the other absolute freedom .. their happiness cannot be taken by the other because it is not given by the other. Osho, being in love.
This is also taught in A course In Miracles - Truth is the same the world over You have the power within you to make your world amazing. Your attitude, perception, thoughts and energy all play a role in what you manifest.