He will not accept it. They went on to say, “A statement, a deed, and an intention are accepted only when they agree with the Sunnah—that is, with the sharia, the very command of Allah and His Messenger. Any word, act, or intention that is not legislated as a Sunnah commanded by Allah is an innovation (bidʿah), something Allah does not love; therefore He will not accept it, and it will be of no avail—just like the deeds of the idol-worshippers and the People of the Scripture.
In the language of the early generations, the term ‘Sunnah’ covers both acts of worship and matters of creed, even though many authors who wrote works entitled ‘Sunnah’ focused mainly on beliefs. Hence the saying transmitted from Ibn Masʿūd, Ubayy ibn Kaʿb, and Abū al-Dardāʾ, may Allah be pleased with them: “Moderation while adhering to the Sunnah is better than strenuous effort in an innovation,” and similar maxims.
All praise is due to Allah, Lord of the Worlds, and may His blessings be upon Muhammad, his purified family, and all his Companions.