The central message of this sermon is that our existence in the midst of "eternities" - past, present, and future - is not a random or meaningless drift, but rather a deliberate design by God. The speaker argues that despite the uncertainty and ambiguity of human life, the Bible teaches that God has predestined us to be part of His plan, which ultimately triumphs over our own intentions and free will. This message advances the belief that God is sovereign and in control, even when it seems that chaos or randomness reigns. The takeaway for listeners is that they are not simply passive observers in life, but rather participants in a grand narrative orchestrated by God, who has sealed them with His promise of salvation and inheritance through Christ.