The central message of this sermon is that time is a gift from God that we cannot control or own, and that our understanding of time should be grounded in the realization that each day is a finite, numbered unit. This message advances the belief that humans are not masters over their own lives, but rather stewards of the time given to them by God. The takeaway the teacher wants listeners to understand is that they must learn to appreciate and make the most of the limited time they have, rather than trying to grasp or control it. This requires a shift in perspective, from seeing time as a commodity that can be owned and managed, to recognizing its fleeting and precious nature, and living accordingly.