The Silver Chair.

In CS Lewis's 'The Silver Chair', Jill & Eustace are told by Aslan to repeat The Four Signs daily in their assigned task as this will keep them on track.

As huge efforts and tiredness take hold - they gradually neglect the signs. Their journey naturally becomes considerably more difficult.

For Christians this is a timely reminder that prayer and Bible reading are essential to make our rather tricky navigation through life more workable.

Lewis was excellent at demonstrating scriptural truths.