If we were to take a 20,000-foot view level of the book of Isaiah, we would see a people falling in and out of obedience to God. They struggle and at moments out right reject him. By the time we reach Isaiah 39, we find Israel in exile. The people are hopeless and have come under God’s judgment. But God’s judgement is meant to draw them back to Yahweh and back to bringing about the promised coming Kingdom of God.
We, too, can find ourselves struggling in our journeys following God. We may lack obedience; we may have chosen work and other things as replacements for God. This, too, can lead us toward exile.
So how do we change course? We do two things. First, we remind ourselves of God’s truth written in Isaiah 40 (see below). Second, we repent of our ways. Essentially, we change our course and direction (see Isaiah 30 below):
The Lord is the everlasting God,
the Creator of the ends of the earth.
He will not grow tired or weary,
and his understanding no one can fathom.
He gives strength to the weary
and increases the power of the weak.
Even youths grow tired and weary,
and young men stumble and fall;
but those who hope in the Lord
will renew their strength.
They will soar on wings like eagles;
they will run and not grow weary,
they will walk and not be faint.
Isaiah 40:28-31
In repentance and rest is your salvation,
in quietness and trust is your strength
Isaiah 30:15