For This Reason (v. 14-16)
Paul is entering into a conclusion for the first half of the book of Ephesians. The preceding three chapters have taught us about the new family to which we, through the Son, now belong. And Paul concludes form this that we ought to be doing two things. The first is that we ought to be worshipping God. The second is that we ought to receive the strengthening of the inner man from the Holy Spirit.
Rooted (v. 16-17)
Now Paul expands on the nature of this strengthening. First, we must constantly remind ourselves that the strengthening of the inner man is revealed in a way that only the eye of faith will see (2 Cor. 4:16-18). Second, we should note that this is a gift from God, not something that we strive to create in ourselves. Third, we should realize what the revelation of God’s glory looks like. The fear is always that God’s concern for his glory makes him a self-centered megalomaniac. But, here we see that God’s glory is revealed in his goodness to us.
That You Might Know (v. 18-19)
The aim of giving this gift is to see us have two things – a knowledge of what it is that God has done for us and, by that knowledge, a deep confidence in our salvation. God desires that we have confidence that establishes us like a try rooted deep into the earth and able to withstand great storms.
This is what happens when you meditate on God’s word daily as the man in Psalm 1 does. You become rooted, established, founded, convinced. Your meditating on the promises of God is a chance for God to argue daily your doubts out of you.
Glory (v. 20-21)
All of this is the work of God, “. . . to him who is able to do.” He is the power that works in us. This has all been a description of the work which God works. So what is left for us to do? We worship.