I'm wondering if belief in the resurrection and belief that Christ is an immortal spirit that can give salvation are kind of one and the same thing..
It is by believing in Jesus Christ is how one is saved.
The fact that the sinner is believing is a work of God, Himself.
John 6:
44No man can come to me, except the Father which hath sent me draw him: and I will raise him up at the last day.
John 3:
18He that believeth on him is not condemned: but he that believeth not is condemned already, because he hath not believed in the name of the only begotten Son of God.
19And this is the condemnation, that light is come into the world, and men loved darkness rather than light, because their deeds were evil.
20For every one that doeth evil hateth the light, neither cometh to the light, lest his deeds should be reproved.
21But he that doeth truth cometh to the light, that his deeds may be made manifest, that they are wrought in God.
John 6:
38For I came down from heaven, not to do mine own will, but the will of him that sent me.
39And this is the Father's will which hath sent me, that of all which he hath given me I should lose nothing, but should raise it up again at the last day.
40And this is the will of him that sent me, that every one which seeth the Son, and believeth on him, may have everlasting life: and I will raise him up at the last day.
John 10:
26But ye believe not, because ye are not of my sheep, as I said unto you.
27My sheep hear my voice, and I know them, and they follow me:
28And I give unto them eternal life; and they shall never perish, neither shall any man pluck them out of my hand.
29My Father, which gave them me, is greater than all; and no man is able to pluck them out of my Father's hand.
30I and my Father are one.