God used various people as prophets in antiquity to make them return from their error and they through the direction of God clarified to them those erroneous concepts that they practiced wrongly to try to please God
God made these people see through his prophets that he totally despised all kinds of ritualism and formal sacrifices and all kinds of ridiculous formalities that instead of pleasing him all he did was unleash his anger.
Isaiah 1: 11-18
What use is it to me, says Jehovah, the multitude of your sacrifices? I am weary of burnt offerings of rams and fat of fat animals; I do not want the blood of oxen, sheep, or goats. Who demands this from your hands, when you come to present yourselves before me to trample my courts? Bring me no more vain offering; incense is an abomination to me; new moon and Sabbath, calling meetings, I can not suffer; your solemn feasts are iniquity. Your new moons and your solemn celebrations are hated by my soul; they are burdensome to me; I am tired of bearing them ...
In ancient times God had ordained sacrifices as a way to obtain forgiveness of sins. however Isaias is not opposing sacrifices, prayer, collective worship is only condemning formal tributes and empty worship that were not accompanied by social justice and true devotion. God what he really wanted was for men to approach him with genuine repentance and a sincere heart not by empty religious rules.
It is for this reason that he warned the people of the following:
Amos 5: 21-22
21 I hated, I abhorred your solemnities, and I would not be pleased in your assemblies.
22 And if you offer me your burnt offerings and your offerings, I will not receive them, nor will I look at the peace offerings of your fattened animals.
In this sense it is important to say that keeping religious rules as solemn tribute from lips and mechanical assemblies do not please God because he does not receive them. God wants his heart and my heart because only then can we obtain genuine repentance.
God rejected the songs and the praises because they were intoned only by their lips and never meant anything to them because they did not do it with the heart
God must be sought with the heart to keep his word but do it with genuine repentance God does not want you to keep rules and arguments of men without sense without repentance he wants you to look for him with all your heart and only then can he keep his word and honor him.