6 Jotham grew powerful because he walked steadfastly before the LORD his God.

Read 2 Chronicles 27:6 Using Other Translations

So Jotham became mighty, because he prepared his ways before the LORD his God.
So Jotham became mighty, because he ordered his ways before the LORD his God.
King Jotham became powerful because he was careful to live in obedience to the LORD his God.