"Whoever has ears, let them hear what the Spirit says to the churches. To the one who is victorious, I will give some of the hidden manna. I will also give that person a white stone with a new name written on it, known only to the one who receives it." (Revelation 2.17)
Most likely what John of Patmos is saying in Revelation 2 is, "and you did the same in your heathen days, you carried an amulet or an "object that protected you from trouble" with supposed supernatural power even with superstitious inscriptions on them like your heathen friends. You thought that they would keep you safe and protect you from harm. Now, you need nothing like that for you are safe in life and in death because you know "a new name," that of the only true God, Jesus Christ." The white stone that Jesus gives will provide entrance to the heavenly feast. It may be also a symbol of the believer's eternal nourishment like the manna in the wilderness. The new name may be a secret until believers enter the presence of the risen Christ in Heaven
In Greek, there are two words for "new" in "new name." There is "neos", which means "new in point of time." A thing can be "neos", and yet exactly like any number of other stones. On the other hand there is "kainos", which is "new not only in point of time but also in point of quality for nothing like it has ever been made before." This new name like nothing before it is written on a white stone and indicates a complete and utter bond to Jesus.