The ascetic souls who retreated at Qumran had disdain for the world and hatred for false believers (if St. John the Baptist had been one of them he would be an exception to the rule). Conversely, the hypocritical Pharisees (there were good Pharisees too, by the way) put their weak faith on public display and profited by it handsomely.
Instead, Jesus wants His followers in the world to be penitential but without being noticed for their works of piety (Matthew 6,1-6.16-18). Pray, fast and give alms without trying to get recognition. With each injunction He promises, “Your Father who sees what is hidden will repay you.”
Although they had little else in common, one shared characteristic of the Qumranites (without getting into the weeds on the “Essene question“) and the bad Pharisees was that they took themselves way too seriously. They were very proud of what they were doing for God (as in the case of the false humility of another Pharisee whose prayer Jesus used to illustrate how not to pray). Sympathy for the suffering sinner was severely… insufficient.
Christians who know what’s happening at the altar can hardly avoid realizing what we have done to God and what He has done for us. If our prayer and penance are making us proud and pedantic instead of magnanimous and modest, it’s likely we need a little love.