So we’re talking about Matt. 16:24.
I think it’s an analogy for detachment, self-sacrifice, and the challenge of being a Christian. We can either live for the enjoyment of this world, or we can “die” to this world and live for God. Living for God is not easy. We have to practice virtue, which requires effort and discipline, and deny ourselves things we want to do or to have. It’s not wrong to enjoy created things, but we tend to use them to excess and in wrong ways, so we have to practice detachment, perhaps use them less, or in some cases not at all. And ultimately our hearts should be centered on God, not on this world.