First you would need to establish that there are contradictions in the bible.
I am familiar with all of them and have reasons why they are not contradictions. I could give you a link to these reasons if you would like.
Familiar with mine?
1. Josiah had four sons, and they are listed in order of birth (
1 Chronicles 3:15). In order, they are Johanan, Jehoiakim/Eliakim,
Zedekiah, and Shallum/Jehoahaz.
1a. Jehoiakim=Eliakim (
2 Kings 23:34,
2 Chronicles 36:4).
1b. Shallum=Jehoahaz (
2 Kings 23:30,
Jeremiah 22:11).
2. Jehoiakim had two sons (
1 Chronicles 3:16), one of whom is named
Zedekiah.
3. Note the important distinction which I will maintain:
Zedekiah in bold is the son of Josiah, and
Zedekiah in italics is the son of Jehoiakim.
"Zedekiah" was 21 years old when he became king and reigned 11 years (
2 Kings 24:18). First assume this is referring to
Zedekiah.
I. Jehoahaz is 23 years old when he begins to reign, and reigns for 3 months (
2 Kings 23:31,
2 Chronicles 36:2).
II. Jehoiakim succeeds Jehoahaz (
2 Kings 23:33-34,
2 Chronicles 36:4).
III. Jehoiakim is 25 years old when he begins to reign, and reigns for 11 years (
2 Kings 23:36,
2 Chronicles 36:5).
IV. Jehoiakim is succeeded by Jehoiachin, who reigns for 3 months (
2 Kings 24:6-8,
2 Chronicles 36:8-9).
V. Jehoiachin is succeeded by
Zedekiah (
2 Kings 24:17,
2 Chronicles 36:10).
VI.
Zedekiah was 21 years old when he became king, and reigns for 11 years. (
2 Kings 24:18,
2 Chronicles 36:11).
VII. The chronological progression from I. to VI. tells us that Jehoahaz is 23 years old (I.) + 3 months (I.) + 11 years (III.) + 3 months (IV.) = 34.5 years old (or at least would be if he were alive) at the same time that
Zedekiah is 21 years old. But 1. from the very top tells us that Jehoahaz is
Zedekiah's younger brother. Therefore
Zedekiah is younger than his younger brother, a contradiction.
Now assume it is
Zedekiah that reigns.
Then this contradicts the prophecy given that Jehoiakim will have no offspring reign after him (
Jeremiah 36:30), since
Zedekiahis his son. And this is not a "bounce" on the throne because he reigns for 11 years.
QED