Psalms 83:18
Psalms 83:1818May they know that You alone, whose name is the LORD, are Most High over all the earth.
is the Watchtower's flagship proof-text for the exclusive-Jehovah-name claim. The verse is invoked to argue that Jehovah is the personal name of God — and that any religion not using the name "Jehovah" cannot be Jehovah's people. The argument is often the door-opening move at the start of a Witness study: "What is God's name? Look at in your own Bible."
The verse does identify Jehovah as the name of God — Christians agree on this. The disagreement is what the verse proves. Many Christian traditions use the name Jehovah: it appears in the King James Version (here, and at , , 26:4), in Reformed confessional documents, and in hymns sung across Protestant traditions ("Guide Me O Thou Great Jehovah"). The exclusive-use claim is a branding argument, not a historical one. And Jesus said "not everyone who says to me 'Lord, Lord' will enter the kingdom of heaven" () — pronouncing the right name is not the same as honouring the person. The fruit test, not the name test, is what Jesus actually proposed.