A bumper sticker reads: “Born once, die twice. Born twice, die once!” What do you think the owner of this vehicle is trying to tell the world?

Being born twice is once physical and once in Christ.  The second birth is eternal and you wont die a second time.

Yes.  Thank you Bruce.  We are born again in Baptism.  The sticker's "second death" probably means, that one will die physically once and because the person is not Baptized, that person will have another death, death of the soul.  This is the death God meant to Adam and Eve.  Even though they ate the fruit, disobeying His command, they didn't die physically.  Some people think God was wrong and ineffective (atheist circles).  However God must have meant death of their souls eternally.

"I am the resurrection and the life: he that believes in me, though he dies, shall live" (John 11:25). This verse comes after Jesus raised Lazarus from the dead. "Then Death and Hades were thrown into the lake of fire. This is the second death, the lake of fire; and anyone whose name was not found in the book of life was thrown into the lake of fire". (Revelation 20:14-15). "Then he will say to those on his left, 'Depart from me accursed ones, into the eternal fire prepared for the  devil and his angels'" (Matthew 25:41). "Assuredly I say to you, this day you shall be with me in paradise" (Luke 23:43) - said to the "good thief" on the cross. Lastly, "For God so loved the world that he gave his only Son, that whoever should believe in him should not perish, but have eternal life" (John 3:16)

Here is some Scripture to back up what y'all are saying.