You have many things to keep: you are attentive to keep your life, your property, your reputation, your family; but above all these things, attend to the keeping of the heart, that it is not entangled with sin.
John Owen, in Indwelling Sin in Believers.
It is quite easy to focus solely on those things that Owen describes here, but to forget the heart. That is, if we are considering our belongings, our schedules, our leisure apart from the affections, desires, and attitudes of the heart, we risk losing much more than those temporal, earthly things.