The word is God----not Savior!!
Which, BTW---if it is as you say--no other Savior---according to JS---there will be other Gods over other planets who must have their Son crucified for that worlds sins also. So That makes many Saviors, not one. However, as I said, the word is God---not Savior.
(Old Testament | Isaiah 45:15 - 21)
15 Verily thou art a God that hidest thyself,
O God of Israel, the Saviour.
16 They shall be ashamed, and also confounded, all of them: they shall go to confusion together that are makers of idols.
17 But Israel shall be saved in the LORD with an everlasting salvation: ye shall not be ashamed nor confounded world without end.
18 For thus saith the LORD that created the heavens; God himself that formed the earth and made it; he hath established it, he created it not in vain, he formed it to be inhabited:
I am the LORD; and there is none else.
19 I have not spoken in secret, in a dark place of the earth: I said not unto the seed of Jacob, Seek ye me in vain: I the LORD speak righteousness, I declare things that are right.
20 ¶ Assemble yourselves and come; draw near together, ye that are escaped of the nations: they have no knowledge that set up the wood of their graven image, and pray unto a god that cannot save.
21 Tell ye, and bring them near; yea, let them take counsel together: who hath declared this from ancient time? who hath told it from that time? have not I the LORD?
and there is no God else beside me; a just God and a Saviour; there is none beside me.
Jesus (Jehovah) was the covenanted God of Israel:
(Old Testament | Exodus 6:5 - 8)
5 And I have also heard the groaning of the children of Israel, whom the Egyptians keep in bondage; and
I have remembered my covenant.
6 Wherefore say unto the children of Israel, I am the LORD, and I will bring you out from under the burdens of the Egyptians, and I will rid you out of their bondage, and
I will redeem you with a stretched out arm, and with great judgments:
7 And
I will take you to me for a people, and I will be to you a God: and ye shall know that I am the LORD your God, which bringeth you out from under the burdens of the Egyptians.
8 And I will bring you in unto the land, concerning the which I did swear to give it to Abraham, to Isaac, and to Jacob; and I will give it you for an heritage:
I am the LORD.