Some argue that the Bible is contradictory concerning how old Ahaziah was when he became king. The argument is that 2 Kings 8:26 says that Ahaziah was 22 years old when he became king, but 2 Chronicles 22:2 says that he was 42 years old when he became king. However, there is a reasonable explanation that solves this alleged contradiction in the Bible.
Ahaziah was twenty-two years old when he began to reign, and he reigned one year in Jerusalem. His mother’s name was Athaliah; she was a granddaughter of Omri king of Israel.
2 Kings 8:26
Forty and two years old was Ahaziah when he began to reign, and he reigned one year in Jerusalem. His mother’s name also was Athaliah the daughter of Omri.
2 Chronicles 22:2 (JKV)
Forty and two years old was Ahaziah when he began to reign, and he reigned one year in Jerusalem. His mother’s name also was Athaliah the daughter of Omri.
2 Chronicles 22:2 (ESV)
The ESV translate’s 2 Chronicles with “twenty-two” and has this footnote:
See 2 Kings 8:26; Hebrew ”forty-two”; Septuagint ”twenty”
Footnote for 2 Chronicles 22:2, ESV
Because the Hebrew characters for forty-two and twenty-two are very similar, it is reasonable to believe that the difference between 2 Kings 8:26 and 2 Chronicles 22:2 is due to a copyist error.
There are some foundational principles that apply to all alleged and apparent contradictions in the Bible. To read more, see Bible Difficulties: Foundational Principles.
To read more answers to alleged and apparent contradictions in the Bible, see “Contradictions” in the Bible Answered.
These books are also excellent resources: