Now he is powerfully able to do abundantly above all which we ask or imagine, according to the power that is working in us,-Ephesians 3:20
God is working out all good according to his purpose through his power. Paul directs his prays toward the church at Ephesus so that they would experience/know of God's power "so that according to the riches of His glory he grants you to acquire strength, powerful ability through his Spirit in your inner being, Christ dwelling in your hearts through faith, rooted and grounded in love, so that you are fully strong to lay hold of, with all the saints, what is the width, length, and height, and depth and know the love of Christ surpassing knowledge so that filled to the extent of all the fullness of God.-Ephesians 3:14-20
The word "so that" is a marker that shows purpose or result. Paul writes long sentences to make sure he covers everything, so to paraphrase, we need to have the God's strength to lay hold of (because it surpasses knowledge alone it requires power through the Spirit, faith, and being rooted in love) to know/experientially deeper the love of Christ which will bring us into the fullness of God.
The goal is that we are filled to the fullness of God, which reflects his image, glory. Why is it important that we must have the strength to lay hold of this love of Christ that surpasses just head knowledge? God loves us, he is working out all things for our good, so he disciplines us for our benefit, conforming us to the image of His Son. Without strength, without power from the Spirit, faith, and knowing the love of Christ we would not endure the proving of our faith that brings us into the fullness of God. The kind of strength that is produced is like that where you can find joy in suffering, knowing God's glory is being revealed in you, he is working in you to accomplish this, because you are chosen to share in his fullness.
To be strengthened in all power according to His glorious might to the extent of all endurance and long-suffering with joy giving thanks to the Father who has qualified you to share of the inheritance of the saints in the light.-Colossians 1:11
We need strength to endure, as the ones God loves he disciplines so that we share in his holiness.-Hebrews 12:10 James writes of joy in the trials as it is proving, testing our faith and the working out of endurance produces maturity.-James 1:2-4 Peter writes there is joy in the trial, as it is for glory, a purification by fire.-1 Peter 1:7 We need strength to endure and remain steadfast. We need strength, the Spirit's power, faith, and being rooted in love, to lay hold of so to know more of his love which gives us strength to endure unto maturity, "... to mature manhood, to the measure of the stature of the fullness of Christ,"-Ephesians 4:12-16 It is this bond of love that leads us into maturity.-Colossians 3:14 The goal is to be filled with the fullness of Christ. He is powerful to do far above all that we ask or imagine, according to the power that is working in us,-Ephesians 3:20