The full quote comes from Jesus in the Gospels:
Jesus told his disciples, “If anyone would come after me, let him deny himself and take up his cross and follow me. For whoever would save his life will lose it, but whoever loses his life for my sake will find it. For what will it profit a man if he gains the whole world and forfeits his soul? Or what shall a man give in return for his soul?” (Matt 16:24-26)
Jesus offered himself on the cross. He gave up comfort, safety and success in this world in order to gain those things in the next world — for himself, but more importantly (especially to us), for us as well.
When Jesus talks about taking up the cross, he is saying to each of us that if we want to be part of that world that he gained for us, we’ll have to do the same — to give up comfort, safety and success in this world. After all, as he says, what’s the point of doing well in this life?
“The land of a rich man produced plentifully, and he thought to himself, ‘What shall I do, for I have nowhere to store my crops?’ And he said, ‘I will do this: I will tear down my barns and build larger ones, and there I will store all my grain and my goods. And I will say to my soul, Soul, you have ample goods laid up for many years; relax, eat, drink, be merry.’ But God said to him, ‘Fool! This night your soul is required of you, and the things you have prepared, whose will they be?’ So is the one who lays up treasure for himself and is not rich toward God.” (Luke 12:16-21)
We brought nothing into this life, and we’ll take nothing out of it (Job 1:21) — unless we take up our cross and follow Jesus.