Contradiction with 2 Samuel 7:12-13
God's promise to establish the throne of David's kingdom forever seems in contrast with the letter from Elijah in 2 Chronicles 21:12, which indicates God's judgment and downfall of Jehoram's rule.
2 Samuel 7:12-13: And when thy days be fulfilled, and thou shalt sleep with thy fathers, I will set up thy seed after thee, which shall proceed out of thy bowels, and I will establish his kingdom.
Contradiction with Psalm 89:35-37
The covenant mentioned here promises David's line to endure forever, which is at odds with the warning in 2 Chronicles 21:12 about Jehoram's destruction.
Psalm 89:35-37: Once have I sworn by my holiness that I will not lie unto David. [that...: Heb. if I lie]
Contradiction with 1 Chronicles 17:11-14
This passage assures the continual establishment of David's kingdom, conflicting with the prophetic message of condemnation in 2 Chronicles 21:12.
1 Chronicles 17:11-14: And it shall come to pass, when thy days be expired that thou must go [to be] with thy fathers, that I will raise up thy seed after thee, which shall be of thy sons; and I will establish his kingdom.
Contradiction with 2 Samuel 23:5
The affirmation of an everlasting covenant with David appears inconsistent with the letter of judgment sent to Jehoram in 2 Chronicles 21:12.
2 Samuel 23:5: Although my house [be] not so with God; yet he hath made with me an everlasting covenant, ordered in all [things], and sure: for [this is] all my salvation, and all [my] desire, although he make [it] not to grow.
Paradox #1
2 Chronicles 21:12 mentions a letter from the prophet Elijah to King Jehoram. The contradiction here is that Elijah is generally believed to have been taken up to heaven (as described in the book of 2 Kings) before Jehoram became king. This creates a timeline inconsistency, as it raises questions about how Elijah could have sent a letter after his departure from Earth.