Miracle working crucifix in the village of Godenovo, Russia In the example of the Lord Who humbled Himself unto death on the Cross, at this juncture of the middle of the holy fast, the Church especially suggests to us humility, which becomes necessary according to the measure of our progress in the virtues, so that pharisaical pride and high-mindedness might not darken our pious labors, and that we might not lose our justification before God, Who looks not only upon our actions, but also upon our thoughts. Therefore, the Church again and again reminds us in this fourth week of the Forty Days Fast, of the publican's humility and the Pharisee's high-mindedness. "Do not be proud of the virtues and do not judge your neighbor as did the pompous Pharisee who thought himself righteous, but rather cry out like the publican in humble contemplation of your sins, "God, cleanse me a sinner and save me."
St. Ambrose of Milan said in the fourth century at the middle of the Forty Days fast: "Give thanks, brethren, to divine mercy for allowing you to successfully reach the middle of the Forty Days Fast. But only they can worthily give thanks who have thus far striven to live as they were taught at the beginning of the Forty Days Fast—that is, those who have striven to ask for the remission of their sins by daily fasting, alms, and church attendance. But as for those who have neglected all this—that is, who have not fasted daily, not given alms, and not earnestly prayed, or prayed without heartfelt compunction—they should not rejoice, but lament and weep."
Archpriest G. S. Debolsky
The Days of Services of the Orthodox Church, vol. 2
Translated by OrthoChristian.com