What is the ruling on one who followed the opinion of Ibn Taymiyyah regarding abandoning prayer, then it becomes clear on the Day of Resurrection that the opinion of Ibn Baz was correct: is he considered a disbeliever or a believing interpreter?

The obligation upon the layman in matters of disagreement is to emulate whoever he trusts among the people of knowledge for their knowledge and piety. He is not sinful if the ijtihad (independent reasoning) of the one he emulated proves to be mistaken. However, as for someone who abandoned prayer relying on the opinion of those who do not consider the one who abandons it an unbeliever, and that opinion was incorrect in the sight of Allah, then he will be an unbeliever abiding eternally in the Hellfire. His belief will not benefit him as long as he knows the prohibition of abandoning prayer. So, the matter is very serious, and the one who abandons prayer is either an unbeliever abiding eternally in the Hellfire, or he is the most evil of the people of the Qibla.