Where can Divine truth be found? Which group has the correct theology?

Moses Law hints at the idea that God is morally perfect (“He is the Rock, his work is perfect: for all his ways are judgment: a God of truth and without iniquity, just and right is He”- Deut. 32: 4).
Therefore, God’s judgment can’t be based upon a person having absolute truth. Rather, it must be based upon the goodness done by such person with whatever amount of truth he was allowed to obtain.
For example, consider the case of the Israelite enemies (the Philistines)-- They captured God’s Holy Ark, and went on to move it from one pagan temple to another (“When the Philistines took the ark of God, they brought it into the house of Dagon, and set it by Dagon”- 1 Samuel 5: 2, KJB).
Yet, although not Levites [and therefore forbidden from touching the Holy Ark], nowhere are we told that the Philistine were specifically punished for the sin of handling the Ark.
On the other hand, once the Ark was back among the Israelites, as soon as the non-Levites opened it up [in order to look inside], they were punished for their sin. As is written:
“ And he [God] smote the men of Bethshemesh, because they had looked into the Ark of the Lord, even He smote of the people fifty thousand and threescore and ten men: and the people lamented, because the Lord had smitten many of the people with a great slaughter”- 1 Samuel 6: 19, KJB.
Why was God lenient with the Philistines, yet stern with the Israelites? Because, unlike the former, the Philistines were ignorant of God’s Law. Therefore, God’s perfect justice wouldn’t hold them accountable for violating a Law they knew nothing about.
Truth be told, Hebrew Scripture teaches that God doesn’t judge whether our theology is right or wrong. Instead, the Creator (blessed be He) chooses to reward the goodness [or punish the evil] we do with what we sincerely believe to be “the right theology”.
And this sort of “Divine relativism” is also implied in the story of Solomon’s wise judgment.
You see, Solomon had to figure out who the biological [and therefore “truthful”] mother of a surviving baby was. Fortunately, the king was wise enough to realize that cold facts didn’t really matter-- the important thing was to find out which of the two quarreling women was willing to act as a real mother; sacrificing herself for the sake of the creature’s well being.
No matter if the latter was the child’s biological mother or not, the humble disposition of her heart would make her worthy of being considered to be the baby’s real mother. As is written:
“Then said the king, The one saith, This is my son that liveth, and thy son is the dead: and the other saith, Nay; but thy son is the dead, and my son is the living...
... And the king said, Bring me a sword. And they brought a sword before the king. And the king said, Divide the living child in two, and give half to the one, and half to the other...
... Then spake the woman whose the living child was unto the king, for her bowels yearned upon her son, and she said, O my lord, give her the living child, and in no wise slay it...
... But the other said, Let it be neither mine nor thine, but divide it. Then the king answered and said, Give her the living child, and in no wise slay it: she is the mother thereof...
... And all Israel heard of the judgment which the king had judged; and they feared the king: for they saw that the wisdom of God was in him, to do judgment”- 1 Kings 3: 23-28, KJB
And something similar happens when it comes to the question of who has the right interpretation of God’s original message to Israel; or which one of the many existing religious establishment (Jews, Samaritans, Christians, Muslims, etc) has the correct theology.
The fact is that the Creator judges people according to their moral performance [in other words, according to the integrity of their hearts]; and not according to their alleged theology.
And that’s why, though a pagan king, the Creator didn’t make an issue of king Abimelech’s faulty pagan theology. Instead, He was lenient to Abimelech, judging him according to the integrity of his heart (exhorting him instead to correct the faulty moral behavior implied in taking Abraham’s legal wife). As is written:
“But God came to Abimelech in a dream by night and said to him, Behold, thou art a dead man, for the woman whom thou hast taken, for she is a man’s wife. But Abimelech had not come near her, and he said, Lord, wilt thou slay also a righteous person? . ..
... Did he not say unto me, She is my sister? And she, even she herself said, He is my brother; in the simplicity of my heart and cleanness of my hands I have done this. ..
... And God said unto him in a dream, Yes, I know that thou didst this in the integrity of thy heart; for I also withheld thee from sinning against me; therefore I did not allow thee to touch her...
... Now therefore restore the man his wife, for he is a prophet, and he shall pray for thee, and thou shalt live [in spite of your faulty theology]. And if thou restore her not [now that you know the truth], know thou that thou shalt surely die, thou and all that are thine”- Genesis 20: 3-7, Jubilee Bible 2000.