Eternal originally did not mean forever. It means outside of time, outside of the temporal.
It is the physical linear processing of our brains that of necessity forces us to apprehend physical time in a linear fashion.
To be is to be forever. That is, we experience, once and only once in the flow and physicality of time. When that ends, time borne of physics will be like a physical object, able to be examined from outside. We will not be subject to its flow, exigencies or decay.
But within time we are becoming, always becoming and not always or automatically becoming someting good. But we are like trees growing, like a painting in progress, becoming until we are.