21 We must inquire whether this fig-tree signifies anything. Listen, my brethren. We find the fig-tree cursed because it had leaves only, and not fruit. In the beginning of the human race, when Adam and Eve had sinned, they made themselves girdles of fig leaves. Fig leaves then signify sins. Nathanael then was under the fig-tree, as it were under the shadow of death. The Lord saw him, he concerning whom it was said, “They that sat under the shadow of death, unto them has light arisen.” What then was said to Nathanael?
You say to me, O Nathanael, “Whence do you know me?” Even now you speak to me, because Philip called you. He whom an apostle had already called, He perceived to belong to His Church. O you Church, O you Israel, in whom is no guile! If you are the people, Israel, in whom is no guile, you have even now known Christ by His apostles, as Nathanael knew Christ by Philip. But His compassion beheld you before you knew Him, when you were lying under sin. For did we first seek Christ, and not He seek us?
Did we come sick to the Physician, and not the Physician to the sick? Was not that sheep lost, and did not the shepherd, leaving the ninety and nine in the wilderness, seek and find it, and joyfully carry it back on his shoulders? Was not that piece of money lost, and the woman lighted the lamp, and searched in the whole house until she found it? And when she had found it, “Rejoice with me,” she said to her neighbors, “for I have found the piece of money which I lost.” In like manner were we lost as the sheep, lost as the piece of money; and our Shepherd found the sheep, but sought the sheep; the woman found the piece of money, but sought the piece of money.
What is the woman? The flesh of Christ. What is the lamp? “I have prepared a lamp for my Christ.” Therefore were we sought that we might be found; having been found, we speak. Let us not be proud, for before we were found we were lost, if we had not been sought. Let them then not say to us whom we love, and whom we desire to gain to the peace of the Catholic Church, “What do you wish with us? Why seek you us if we are sinners?” We seek you for this reason that you perish not: we seek you because we were sought; we wish to find you because we have been found.
Source: Tractates on the Gospel of John (New Advent)