"Saved to the uttermost" in Hebrews 7:25 is an expression that has the capability of meaning “saved forever," but the author had other words and phrases he prefers to use in this book to convey that.
But what is so strongly and repeatedly emphasized throughout Hebrews is we are people on a temporary trek, a sojourn, a pilgrimage in this temporal wilderness world.
And that temporal trek is to have ramifications that are eternal in impact.
In that vein, "saved to the uttermost" means "to the nth degree," saved unto the very end, saved unto the successful completion of that pilgrimage.
Hebrews is a New Testament book that just oozes out of its seams with OT quotations, allusions and images (of all the controversial issues Christians will find to argue about concerning Hebrews, at least no one disputes that!)
But there is ONE Old Testament scene that especially stands out as a bold, panoramic backdrop to the whole epistle: It's the children of Israel at Kadesh-Barnea, on the very threshold of entrance into their inheritance in the Land of Promise (Numbers 13-14).
Some have the chutzpah to call it a type, while others may refer to it as simply a backdrop, a foreshadowing, or the Old Testament "counterpart" of the perilous dilemma confronting these New Testament pilgrims and sojourners.
The point is, God intends for us to draw upon certain parallels between the two scenes. He wants us to make careful note of the points of similarity, and learn certain truths from them.
Israel wasn't just redeemed by the blood of a lamb from their cruel bondage in Egypt.
God had an exalted goal and purpose for them from the start. They were headed to a glorious INHERITANCE that God, Himself, desired for them in another land. He had a full-orbed salvation in His heart for them; a salvation without precedent or parallel; A “SO GREAT SALVATION."
It was a salvation He intended for the whole nation: redemption by blood from cruel slavery UNTO A GLORIOUS INHERITANCE in another land.
That inheritance was never intended as a mere “optional extra” that God’s children could pursue or refuse as they saw fit, although THEY clearly treated it as such. God expected them to choose for themselves what He had so generously chosen for them.
Exodus 3:8: "I am come down to deliver them out of the hand of the Egyptians, AND to bring them up out of that land UNTO A LAND FLOWING WITH MILK AND HONEY; unto the place of the Canaanites, and the Hittites, and the Amorites, and the Perizzites, and the Hivites, and the Jebusites."
Exodus 15:17 ("Song of Moses): "Thou shalt bring them in, and plant them in the mountain of thy inheritance, in the place, O LORD, which thou hast made for thee to dwell in, in the Sanctuary, O Lord, which thy hands have established."
Deuteronomy 12:9-11a "For ye are not as yet come to the rest and to the inheritance which the LORD your God giveth you. But when ye go over Jordan, and dwell in the land which the LORD your God giveth you to inherit, and when he giveth you rest from all your enemies round about, so that ye dwell in safety; Then there shall be a place which the LORD your God shall choose to cause his name to dwell there . . ."
Joshua 1:2-5, 6 "Moses my servant is dead; now therefore arise, go over this Jordan, thou, and all thy people, unto the land which I do give to them, even to the children of Israel. Every place that the sole of your foot shall tread upon, that I have given unto you, as I said unto Moses. From the wilderness and this Lebanon even unto the great river, the river Euphrates, all the land of the Hittites, and unto the great sea toward the going down of the sun, shall be your coast. Be strong and of a good courage: for unto this people shalt thou divide for an inheritance the land, which I sware unto their fathers to give them.”
But, sadly, not all of those He redeemed would ever enter in and enjoy that inheritance. Not all who were redeemed would be saved "to the uttermost."
“So we see that they could not enter in because of unbelief” (Hebrews 3:19).
As wonderful as it is, our gracious Lord did not just redeem us from the slave market of sin by the shed blood of the Lamb. There is a GOAL TO OUR CALLING; we are “redeemed for a revealed purpose;” a purpose that is dear to His heart.
He has redeemed us FROM a slavery most cruel, by the blood of the Lamb, UNTO A GLORIOUS INHERITANCE in another land.
This is a goal that God, Himself, most earnestly desires for us (Luke 12:32: "Fear not, little flock; it is the Father's GREAT HAPPINESS to give you the kingdom!")
And, if our hearts are aligned with His, we will be continually and earnestly seeking the same as long as we draw breath on this earth.