How much is it worth knowing the Law without correct Theology?

The Mishna states:

משנה מסכת סנהדרין פרק י משנה ב

שלשה מלכים וארבעה הדיוטות אין להם חלק לעולם הבא שלשה מלכים ירבעם אחאב ומנשה

Three kings and four commoners have no part in the world to come. The three kings are Yerovam, Ahab and Menashe.

פירוש המשנה לרמב"ם מסכת סנהדרין פרק י משנה ב

[ב] הזכיר את אלו מחמת גודל מעלתם בחכמה, והיה חושב מי שיחשוב שברוב חכמתם וזכות התורה שהיו יודעים אותה ידיעה גדולה יש להם חלק, לפיכך השמיענו שיסודות האמונה נתקלקלו אצל אלו והיו להם ספקות במקצתם ולפיכך נדחו מחיי העולם הבא.

Rambam explains:
These three are singled out because of their great wisdom. Someone might think that because of their great wisdom and the merit of the Torah they knew they would have a part in Olam Haba. The Mishna tells us that the foundations of our belief were corrupted by these men and they had doubts about some of those foundations and were therefore excluded from the life of Olam Haba.

Professor Chaim Kreisel recently published the second volume of Livyat Chen, an encyclopedic compendium of Jewish Philosophy written by Rabbi Levi Ben Avraham in early 14th century Provence. RLBA was singled out and persecuted by Rashba in his war against philosophy. He was however revered by other great scholars of his time such as Meiri and R. Yitzchak de Latif.

Discussing the prohibition to anthropomorphize God, he condemns those who do so out of ignorance or erroneous conclusion. He argues that it is no different from idol worship which is a form of anthropomorphism. Man has brains and freedom of choice and is therefore obligated to learn the truth. Ignorance is no excuse. One should not respect the opinion of past generations for many things are known better by later generations. He goes on to quote a plethora of verses in Tanach that support this attitude. Here is a paraphrase of the interesting part I have been leading up to;

It is my opinion that Menashe and Yerovam were wise only in the laws and rituals of the Torah and accepted things literally. That is why the rabbis praised them in their knowledge of Kulot and Chumrot. [IOW they knew how to legislate – pasken - DG]. That is why the Gemara in Sanhedrin 106b says that there is no great advantage in asking many questions [about rituals]. God wants us the serve Him with our heart. [DG – Focusing too much on the details of the ritual is not a virtue]. They also say that Do’eg and Achitophel [two of the four commoners mentioned in the Mishna] did not arrive at proper conclusions in their Halachik learning. This shows that they did not understand the reasons for the Mitzvot and did not understand true philosophic discourse. That is why the Rabbis said that Do’eg forgot his learning by the time he died. Philosophic insight is unforgettable. [See MN 1:62 - In works on Metaphysics it has been shown that such knowledge, the perception of the active intellect, can never be forgotten: and this is meant by the phrase "his learning remains with him."] They were also not seeking to attain the truth with their learning, they did not delve into the depths of the ideas, they did not abstract; all their thoughts were expressed in just words without conceptualizing. They therefore did not understand the secrets and truths but let themselves be misled into what they could sense. That led them to anthropomorphism and Avodah Zara; they followed the nonsense of the nations and mistook the image as the maker, the plant as the planter. They divided up the earth by saying that different forces emanating from the stars and spheres had sway on the different parts of the world and worshiped them.

This is a fascinating piece where he clearly had the Pirush Hamishna in front of his eyes and explained it at length. It is incongruous how he equates the non-philosophical legalist with the ignorant idolater. Both have no Olam Haba!