Have you ever seen a grown-up act like a child?
They throw these fits and act irrationally.
It is always out of place, that is what Paul is saying here.
As believers, our goal is to mature in our faith, which means we don’t always get it right, the same as we don’t always get adulting right, but we are in the process of maturing.
To look and act a certain way.
It is about calling and reflecting God's goodness in all we do.
When believers allow their upbringing, circumstances or experiences to determine their actions it looks strange.
Paul is calling us to be people of actions and not reactions.