It is recorded in the Gospel of Mark 8:36
For what shall it profit a man, if he shall gain the whole world, and lose his own soul?
Presuming Jesus really spoke these words what do you think Jesus meant and why?
Here's two very different examples:
1. Suppose you are a webcomic author (I'm using this one, because I actually KNOW a webcomic author who did this), and you're struggling to be extra-woke and liberal so that you can appeal to all your fans. You know, because image and reputation is all important. So you fill your comic with blacks, whites, basically the entire LGBT spectrum as quotas (you have a trans person, a gay wedding, some lesbians and bisexuals), you have rednecks and all sorts of people in your webcomic town. You even have a girl who is convinced she is an elf or something, and another who lives in a space station. But you have unpleasable fans, who constantly demand this or that, and you are always trying to meet their needs. This can happen in any public service job, even working at a library, but we want to use this example. So at one point, you have a bikini shot of a girl who while cute is a bit bigger than normal. You draw the comic, showing some of her angst about her body, and you think you did okay. The fans however tell you "She isn't fat
enough," and that you should just go die. So you stab a fork through the hand you use to draw with. You have allowed public image to override your artistic vision. You've lost your soul.
2. For a more conservative example, suppose you are an average family guy working about 30 hours, plus you fill in as needed for extra, but it's typically an understood that you want to get home and look after your loved ones in addition to supporting them financially. Basically, you had a dad who worked so much that you never saw him, and you don't want to be like that. Then the boss decides they like your work, but they want more of it. So they want you working 40 hours on a regular basis, and more importantly they want you working at hours that are incompatible with seeing your wife and child. Basically, you're working 40 hours on graveyard shift and unable to see your family that you love. You don't want to be fired, so you go along to get along. You've also lost your soul to please the world.
Jesus calls us, not to be people-pleasers but to "let our freak flag fly" as many of the LGBT groups say. Only, many of them have gotten into the habit of trying to outdo each other or conform to a certain type, so that's out too. It's what is meant by "taking up your cross and following", all of us have burdens we can't let the world see. But these things tend to become sins based on how we deal with them.