Bring no more vain offerings; incense is an abomination to me. New moon and Sabbath and the calling of convocations— I cannot endure iniquity and solemn assembly.
Isaiah 1:13

Sacrifices were usually a time for celebration, not mourning. (See Nehemiah 12:43, for example.), but there's no point in sacrificing and celebrating if God isn't there to celebrate with us. Isaiah 1:11-15