…he saw there a man which had not on a wedding garment… – Matthew 22:11

The day of comfort to His saints is also the day of vengeance of our God. He who comes to comfort all that mourn comes at the same time to smite the rebellious with a rod of iron. The judge begins by seeing, “He saw there a man.” The parable represents but one such man as present, yet the king saw him at once, he fixed his flaming eyes on that one. I suppose it was a greater crowd than this, but the king fixed his eyes on the solitary offender at once. Does the parable speak of only one because we may expect to find only one hypocrite in a church? Alas! there have been many such at the wedding feast, but one only is mentioned to show us that if there were but one, God would find him out; and being many, the sinners in Zion may be the more sure that they will not escape. It is possible that none of the guests may have noticed the man’s garments; the parable makes no remark upon any expostulations made to him by others; perhaps they were all so taken up with the sight of the king, and so glad to be at the feast themselves, that they had no heart to make remarks upon others. But this is certain, that the king detected at once the absence of what was requisite to the marriage feast. It was not the presence of anything offensive, but the absence of something which was requisite. He did not say to the unworthy guest, “Thou hast rags upon thee,” or “thou art filthy.” or “thou hast an unwashed face”; he enquired solely into the absence of the peculiar badge which denoted a loving guest. God will judge, and does continually judge His church upon this question, the absence of what is absolutely necessary to being a Christian, the absence of honouring the Son, and obeying the Father…The one thing needful is to accept loyally the Lord as King. ~ C.H. Spurgeon

https://www.blueletterbible.org/Comm/spurgeon_charles/sermons/0976.cfm