In plain words
Because He is there within, the chariot called the body moves along. If the driver sits outside and tells it to move, will the car move? Just because he sits inside the car, does he become the car? No, no. The one who drives must sit inside, not outside. Seated on the throne called the heart, He drives the chariot called the body.
God Is Right within Us
God is right within us. He may be seen everywhere. But from where is He seen? Reflection of the inner being. The One who is within oneself is the One seen outside. If He is not within oneself, how can He be seen outside? He Himself is ‘Ekaṃ sat viprāḥ bahudhā vadanti.’ He who is, is One alone; He went on appearing to the ṛṣis in many names and forms. As we develop the feeling of the one Ātma: ‘All are brothers and sisters! All bodies are like temples! God is not somewhere outside. The body itself is the temple’: this feeling we must hold. We must believe this firmly. Whatever pain we cause anyone, we must look on it as pain caused to ourselves. For the God in all bodies is one alone! How must we see such a God? When we develop the principle of Prema within us, everything appears full of Prema. If we put blue glasses on our eyes, the whole world looks blue. But is the whole world blue? No! What we see is the colour of the glasses we have put on. So when the heart is turned to Prema, the world turns to Brahman. If we want to see the whole world as Brahman, first of all we must turn the heart to Prema. Only to one who lacks that Prema does the world appear in all kinds of names and forms. This diversity is not Satya. Oneness alone is Satya. That is the Advaita Śaṅkara taught. So every human being must understand well the principle of oneness.