Be rooted and grounded in love so that you may be filled with the fullness of God. The Church commemorates today St. Bonaventure, also known as the “Seraphic Doctor.” Born in Bagnoregio, Italy, he entered the Franciscan Order at the University of Paris where he was a lecturer. He became the Minister General of the Order and later the Cardinal Bishop of Albano. He authored biblical commentaries and many ascetical and spiritual treatises, the Itinerarium mentis in Deum (the Soul’s journey into God) and Breviloquium being his masterpieces. He is considered the greatest exponent of mystical theology in the Middle Ages.  
The above words of St. Paul found in today’s First Reading must have been heard by St. Bonaventure as if directed to him because he tried his best to live them in his life, both as a scholar and as a friar. A gifted scholar that he was, St. Bonaventure used his talent to try to ‘know’ God so that he could be united to God. In the Itinerarium, Bonaventure demonstrates how a human person’s ‘knowledge’ of God is ordered towards union with God. This is possible, he says, because the essence of knowledge is love. One can only know God by loving God. This is exactly what Paul is urging the members of the Ephesian community to do. In order to come to the full knowledge of God (to be fully immersed in God), one has to be grounded in God’s love.
God is love. He/she who claims to know God must love (cf. I John 4:8). This is why in the medieval debate regarding which property (quality) of the soul is superior (knowing or loving), St. Bonaventure picks loving. Loving as an act is that is directed outwards, an act that requires of one to get out of the self, so to speak. It is through acting towards the other that one closely mirrors God since God is love (cf. I John 4:8). In other words, loving is the human action that unites him/her more with God.