Yes - JWs are hppy - because they live in the "spiritual paradise"
WT 2015-07-15 page 9 § 13
The existence of a spiritual paradise in the midst of a wicked, corrupt, and loveless world is a modern-day miracle! The wonders about Jehovah’s organization, or “Zion,” and the truth about the spiritual paradise must be joyfully passed on “to future generations.”