The Bible’s track of history is unique in that it doesn’t just show when the people written about did good, it also shows when they did bad. David was good, until he got into that affair with Bathsheba, and indirectly got her husband killed in battle. He was called out on that part by a prophet speaking in behalf of God, and the only reason he lived was that he repented, but he still lost their first child because of it.

Solomon was the king with a thousand wives. He asked God for smarts when presented with an option to ask for anything and be granted it, and he was granted that and more for thinking soiritually and not materially, but the he started getting into the whole wives and concubines thing. Another example of “started out good, but then got sucked into doing bad”, as he was given advance prophecy that Israel would be broken into pieces over this. Which happened when his son took over and made things worse.