[MurphsLaw]

The key to understanding that is that we can not save people’s souls- look at the verse- it says “whoever brings back a sinner from the error of his way will save his soul”. We don’t save people- we have no power to save their souls-

Where do you see in this verse that it says “man” is who saves the Soul? …. The Bible would not say that- the verse would be in error IF it implied that. You seem to be disqualifying the verse because of an interpretation you are making… So no, the verse never intends that “man” WILL saves souls…

  Rather that the wanderers Soul is “saved” ONCE he is brought back into believing in the Truth –again. The brethren just assist in that turn around... but the Spirit must reclaim any wayward soul.

  The outcome of this verse means… 

(Any) among you – those who HAVE
BEEN saved- (with the Truth) 

That those who wander away form that Truth - turn away from God- as sinners– (Leaving the Truth -possibly permanently)  UNSAVED

Can be brought back from His error of his way - By which his Soul is saved from death... (the Operative words being WILL SAVE from – and obviously not meaning saving ones physical life-
as we don’t die physically when we turn away from God by sinning…usually) - but will save... doesn't mean immediately either...

And the verse does not imply a limitation on how many times a sinner can be brought back to the Truth- in this saving manner. 

  Another key to understanding the Eternal security of Salvation is that When a person is saved- they are given “Eternal Life”- Would be kind of cruel to suggest that the word “Eternal” means “only as long as” someone toes the line- When you are saved- you pass from death unto life- unto eternal life 

Well, I guess it would be cruel if you believed in not losing your salvation. But again, you're pre-supposing that you get to call yourself eternally saved forever. It's not in the Bible. Jesus never taught that way as the moderns now interpret it. And logic tells you - if something so important such as Guaranteed Eternal Salvation existed- it would be clearly stated in Scripture in the Bible.. AND OFTEN- without having to do the interpreting Game to decode a meaning...
Furthermore, if you understand Salvation as a life process… you can understand John 15 better:

  9 “As the Father has loved me, so have I loved you. Now remain in my love. 
10 IF you keep my commands, you will remain in my love, just as I have kept my Father’s commands and remain in his love. 
11 I have told you this so that my joy may be in you and that your joy may be complete.  

DOES THIS sound like absolute guarantee of Salvation from John? No it does not. It IS CONDITIONAL… 
“IF YOU KEEP my Commandments… you will remain…. 
If you DON'T keep God's commandments, do you still remain? I don’t think so… once you are in Christ you get to remain in him... But if you do not obey the commandments...you will NOT REMAIN in Christ. Now maybe you will say you are still saved...
But I don't think so.
Also The word for Soul in this verse (psuche) is “Life”- and doesn’t mean spirit or soul in the sense of the eternal soul- Wherever it is used it mean the life of a body which is subject to death- 

Strongs Greek shows the Bible using psuche 102 times… yes sometimes physical…but in our verse  Ja 5:20 Strong’s assigns it to spiritual. 
I guess anyone can make it say what they want... but then the belief is in their interpretive abstract assent- and away from the substance of the word made Flesh...incarnate Flesh.

[Bob434]

you asked for verses that give assurance, i gave them to you- Christ never loses actual souls that are given to him by the father- if he did, the bible would be a lie-

“[28] I give them eternal life, and they will never perish, and no one will snatch them out of my hand. [29] My Father, who has given them to me, is greater than all, and no one is able to snatch them out of the Father’s hand.”

Strong assigns “Spirit” to the word psuche- Spirit is not the soul- Spirit is what makes us us- it is out life- Here is the definition from the word:

“The Spirit gives life; the flesh counts for nothing. The words I have spoken to you—they are full of the Spirit and life.”

““Jehovah God formed man from the dust of the ground and breathed into his nostrils the breath of life, and man became a living soul.””

The “Breath of life” Is The Spirit that is given by God- the Hebrew Word is Neshamah Meaning “Spirit”

[[pre-supposing that you get to call yourself eternally saved forever. It’s not in the Bible]]

It is in the bible- botrh as direct proclamations, and infered as in the explanation about Christ never losing any of His flock- IF it is possible for a saved person to lose hteir salvaiton, and die immediately and wind up in hell- then the bible is a lie- God specifically proclaimed that NONE of those He gives to Christ will be lost-

[[DOES THIS sound like absolute guarantee of Salvation from John?]]

That verse is not about salvation but remaining in a close relationship with God- We as Christians can walk away from His love and protection- but we are still saved- just as a son can walk away from their parent’s love and protection and still be their son-

John 15 is not about losing salvation- there are many sermons and articles on this fact- it is simply sayign that if a person walks away from God’s love, and is not bearign fruit as a result- they will not be under His love and protection- it doesn’t mean they lose His love though- God will always love them because they are His- The way to remain “UNDER” His love is to keep His commandments (but again this was to the Jews- Whom he had just told that they must Accept Him as Savior in order to ‘abide in Him’- those that don’t will be burned up because they are unsaved- always were- and had no intenion of beign saved- These unsaved were Jews that who took other gods-

Vs 10 is a condition of descipleship, not salvation- just as a son walking away from family is a condition of departure from the family, but not from the blood line-