When Owen Barfield described the evolution of consciousness, he used 'evolution' in a pre-Darwinian sense of a developmental change analogous to the fertilised egg 'unfolding' to become a mature, adult organism.
In other words, Barfield regarded evolution not merely as change, but as purposive change, change with an aim or 'teleology'.
If the evolution of consciousness has a unified purpose and aim (isn't just a different purpose and aim for each entity), then this implies that there is a deity - as the source of purpose. Therefore, the evolution of consciousness is a consequence of some divine plan.
What could this divine plan be? For many Christians it will be 'theosis' - or the process of Men becoming more and more like God; aiming at becoming Sons and Daughters of God.
So, the evolution of consciousness is about our consciousness - that is, our way of thinking - becoming more divine, more like God's way of thinking.
This is a measure of the importance of the evolution of consciousness; and the need for it. Our life on earth is about 1. Accepting that salvation which is the gift of Jesus; and 2. Theosis - or working on the task of making ourselves more divine in our nature.
The moral aspect of theosis is very well known - but the consciousness aspect of theosis is almost wholly neglected - especially in mainstream Christian life.
In theosis we are not supposed only to 'do the right things', nor even to think the right things - but to think in the right way...
We should strive for a divine quality of thinking.
That is how important the evolution of consciousness is.