For this cause I bow my knees unto the Father of our Lord Jesus Christ, of whom the whole family in heaven and earth is named, that he would grant you, according to the riches of his glory, to be strengthened with might by his Spirit in the inner man; that Christ may dwell in your hearts by faith; that ye, being rooted and grounded in love, may be able to comprehend with all saints what is the breadth, and length, and depth, and height; and to know the love of Christ, which passeth knowledge, that ye might be filled with all the fullness of God.

Ephesians 3:14-19 (KJV)

The Love of Christ, i.e. the love that Christ is the source of, is far beyond mere human knowledge. It is unfathomable, it can only be revealed and realized by the work of the Holy Spirit.  The fullness of God is realized only through the fullness of Agape. This is the perfect love that expels fear.   It never keeps record of wrong done to it. Faith is made effective by Love