As to the part about Jehovahs Witnesses and them seeming to wait for the Kindom of God: I don't know much about them specifically, but it might have something to do with both Lutheran and Calvinist religious concepts that contradict the idea of 'good works' as an essential part of Christian life.
Predestination is a common theme; God is all-knowing, and He already knows whether you will fail or succeed in this life, and whether it will be heaven or hell for you in the end. So why overtly labour for a temporal kingdom here, when having an honest faith will grant you an eternal stay in heaven, which is a perfect setting? Add to this Luther's concept of Sola Fides and you'll end up with a focus on the next life.