It literally means to become alive after one has died.
Jesus gave up His life on a Roman cross after having been brutally tortured and publicly humiliated. He was sinless, perfect in every way, was actually God-in-the-flesh, and yet, gave up His life for a reason. He came to make a substitution. His life given in substitution for your and my imperfect, sinful and godless life. We’re walking dead.
When we realize that we’re spiritually “done for”, we can have hope. Because when Jesus gave His life as a substitution for ours and was resurrected from the dead, we can be resurrected from the dead with Him. As in, you can come alive spiritually. It’s all in you making it personal by repenting and believing. Believing that His death and resurrection was enough for you.
Resurrection means the dead come to life. It was first in Jesus. It can now, by substitution, be in you.