FAQ #Death

Lucia was asking about sin and death only being around since Adam. Genesis for Ordinary People highlights Romans 5 and talks about sin being in the world before the law that Adam was given, but what about I Corinthians 15: 21-22 which says, 'For since by a man came death, by a man also came the resurrection of the dead. For as in Adam all die, so also in Christ all will be made alive.'?

So if Adam wasn’t the first person to live and die, did God create men sinful because men only die because they sin? And if there were men before Adam they must have been sinful because they died.