Death sucks.
Even if you believe that life is eternal, death still sucks.
Before raising Lazarus, Jesus wept for him. Before facing His own death and resurrection, he begged God to take the cup from him.
Because death, even though life comes after it, still sucks.
Death is a corruption of creation. Even though it has been ultimately defeated, we still (for the time) feel the sadness and weight of it. We know, deep down, it’s not how things are supposed to be. It reminds us of our fallen state.
You may get along even better after fighting and then making up with someone, but the sting of the fight is still there. You still feel the consequences of the error, even after all is set right.