"And I pray that you, being rooted and established in love, may have power, together with all the saints, to grasp how wide and long and high and deep is the love of Christ, and to know this love that surpasses knowledge - that you may be filled to the measure of all the fullness of God." NIV translation
Paul continues to share his prayers for the Ephesians as we see that he now prays for them to know how much God loves them. This is more than a head knowledge as it is of the heart. We see that the power to grasp this comes from God and the purpose is so that we will grow closer to Him.
"Now to him who is able to do immeasurably more than all we ask or imagine, according to his power that is at work within us, to him be glory in the church and in Christ Jesus throughout all generations, for ever and ever! Amen." NIV translation
Paul concludes his prayer by reminding the Ephesians (and us as well) that El Shaddai (God Almighty) is the one who created all things and therefore owns everything.
He can do more than we could ever even dream of and that same power is alive in us as He is in us through the Holy Spirit. The purpose of all things is to bring Him glory.