There is no question of believe. Don't bring this question-belief. It is law. Just like there is government, you believe or not believe, who cares for you? That is government. Similarly, you believe or not believe, there is God. If you don't believe in God and do independently whatever you like, then you'll be punishable.
-Radio Interview -- July 27, 1976, London

देहिनोऽस्मिन्यथा देहे कौमारं यौवनं जरा ।
तथा देहान्तरप्राप्तिर्धीरस्तत्र न मुह्यति ॥ १३ ॥
As the embodied soul continuously passes, in this body, from boyhood to youth to old age, the soul similarly passes into another body at death. A sober person is not bewildered by such a change.
-BG 2.13