Paul is telling us where the focus of our attention needs to be. We can give our minds over to a lot of things, for instance, to our jobs - and there is a place for that. We can give our minds over to physical things - exercise, eating well, and so forth - and there is a place for these, too.
Indeed, humans need to set their minds on many things, but they need to be prioritized correctly - put into the right niche and position. Then each of these things has to be seen in relation to the Kingdom of God. Our priorities must be set according to this standard - the overriding goal of our Christian lives.
"Set your mind on things above" adjusts the focus of our attention so that we do not become distracted by things that are less important for any longer than needed, so that they occupy the right proportion and amount of time in our lives.