Jesus performed many miracles, healings and even raised people from the dead before Lazarus' resurrection, but this act uniquely prepared His disciples--and us--to have faith in His resurrection power.
The thing about resurrection power is that it is greater than any power we know. Not only does God have the power to create, but the power to recreate!
What can a God with life-saving power do?
What CAN'T a God with life-saving power do!?