This then is hypocrisy;—not simply for a man to deceive others, knowing all the while that he is deceiving them, but to deceive himself and others at the same time, to aim at their praise by a religious profession, without perceiving that he loves their praise more than the praise of God, and that he is professing far more than he practises. And if this be the true Scripture meaning of the word, we have some insight (as it appears) into the reasons which induced our Divine Teacher to warn His Disciples in so marked a way against hypocrisy. An innumerable multitude was thronging Him, and His disciples were around Him. Twelve of them had been appointed to minister to Him as His especial friends. Other seventy had been sent out from Him with miraculous gifts; and, on their return, had with triumph told of their own wonderful doings. All of them had been addressed by Him as the salt of the earth, the light of the world, the children of His kingdom. They were mediators between Him and the people at large, introducing to His notice the sick and heavy-laden.

And now they stood by Him, partaking in His popularity, perhaps glorying in their connexion with the Christ, and pleased to be gazed upon by the impatient crowd. Then it was that, instead of addressing the multitude, He spoke first of all to His disciples, saying, “Beware of the leaven of the Pharisees, which is hypocrisy;” as if He had said, “What is the chief sin of My enemies and persecutors? not that they openly deny God, but that they love a profession of religion for the sake of the praise of men that follows it. They like to contrast themselves with other men; they pride themselves on being a little flock, to whom life is secured in the midst of reprobates; they like to stand and be admired amid their religious performances, and think to be saved, not by their own personal holiness, but by the faith of their father Abraham. All this delusion may come upon you also, if you forget that you are hereafter to be tried one by one at God’s judgment seat, according to your works. At present, indeed, you are invested in My greatness, and have the credit of My teaching and holiness: but ‘there is nothing covered that shall not be revealed, neither hid, that shall not be known,’ at the last day.”

Ven. John Henry, Cardinal Newman (1801-1890)

from Profession without Practice
Parochial and Plain Sermons Volume I Sermon 10 (1834)