God made Jesus Christ Lord in the resurrection (Romans 1:4) and because of that he appointed him the-Son-of-God-in-power. We now as sons of God can be strengthened in the immensity of HIS authoritative power. That is the source of our strength (Ephesians 6:10). Then we walk in that power and exercise our operation of it by 1) our roots being strengthened (in the Word), 2) being built up in him by his Spirit, 3) being established in faith, 4) abounding with thanksgiving and then 5) standing our ground (Colossians 2:6-7 and I Cor 16:13). The purpose of this strengthening is to bring glory to God.