Although the people were doing the performances required of the Lord in Isaiah's time, the remembrances and symbolism were not effecting the personal devotion and changes the Lord desired in them. They are becoming hypocrites with a public face of piety and harboring evil in their hearts.
Ah sinful nation, a people laden with iniquity, a seed of evildoers, children that are corrupters: they have forsaken the Lord, they have provoked the Holy One of Israel unto anger, they are gone away backward.
10 ¶ Hear the word of the Lord, ye rulers of Sodom; give ear unto the law of our God, ye people of Gomorrah.
11 To what purpose is the multitude of your sacrifices unto me? saith the Lord: I am full of the burnt offerings of rams, and the fat of fed beasts; and I delight not in the blood of bullocks, or of lambs, or of he goats.
12 When ye come to appear before me, who hath required this at your hand, to tread my courts?
13 Bring no more vain oblations; incense is an abomination unto me; the new moons and sabbaths, the calling of assemblies, I cannot away with; it is iniquity, even the solemn meeting.
14 Your new moons and your appointed feasts my soul hateth: they are a trouble unto me; I am weary to bear them.
15 And when ye spread forth your hands, I will hide mine eyes from you: yea, when ye make many prayers, I will not hear: your hands are full of blood.
Although we can make a good performance o righteousness in the eyes of others, the Lord sees into our hearts and knows if we are truly devoted to him and his purposes.