The "rest" in Hebrews

 "For we who have believed do enter that rest," Hebrews 4:3.

What if the "rest" in Hebrews is like the "already, not yet" view concerning the kingdom?  Though the kingdom is future, as to its full realization and manifestation, it has a present form in this world, being its representation in the people of God (the ambassadors) and the authority of Christ to give eternal life to those who believe in Him.  We enter that "rest" now by faith; we are transferred to the kingdom now, but the experience of that rest in the present depends on our continuing in the faith.  And so, the rest has an already, not yet reality to it.  The not yet is the future rest in the kingdom, while the already is the present rest we can experience if we continue in the faith.

I'm going to say the rest is the "world to come": "He has not put the world to come, of which we speak," Hebrews 2:5.  The "rest" that Israel didn't enter was the land because of unbelief.  However, the author of Hebrews makes reference to a Psalm that reveals that Joshua did not give them rest (after they did enter the land) because there is reference to a future day: "if Joshua had given them rest, then He would not afterward have spoken of another day.  There remains therefore a rest for the people of God." Hebrews 4:8-9  So the "rest," I believe, ultimately looks to the world to come.  And that rest is entered by faith--those who believe:  "For we who have believed do enter that rest," Hebrews 4:3.  Therefore, the author of Hebrew's readers should not think that they have come short of that rest by faith in Christ alone (thinking they must come under the Law to qualify for entry, which would be like the Israelites who did not believe the promise given to them, concerning entry):  "Therefore, since a promise remains of entering His rest, let us fear lest any of you seem [think?] to have come short of it.  For indeed the gospel was preached to us as well as to them; but the word which they heard did not profit them, not being mixed with faith in those who heard it." Hebrews 4:1-2 

They needed to press on knowing what they have and not cast off their confidence which has great reward: "knowing that you have a better and an enduring possession for yourselves in heaven.  Therefore, do not cast away your confidence, which has great reward." Hebrews 10:34-35