First, yes salvation is not only a change of what we think and believe. However, our character can have a lot to do with what we want to believe. So, when Jesus saves a person, God changes the person's character so the person is able to believe things of God's word . . . but also do what the Bible says to do.
For only one example, a selfish person might not be able to believe in forgiveness, though the Bible clearly does say,
"forgiving one another, even as God in Christ forgave you." (in Ephesians 4:32) And even ones who have become Christians still might be lazy forgivers, since they still are not strongly loving; and so they might say oh I can't forgive because I am not God. But God in us makes us like Himself so we forgive
"even as God" who in us shares with us His nature and ability of love.
So, what we believe can be because of our character more or less selfish and because of how loving we really are or aren't. And becoming saved includes changing our nature, then, so we can live the love meaning of God's word, and not only change in how we explain things
You asked, it seems from a quote, "What" the Holy Spirit is. And I think you got a good answer, how the Holy Spirit is a Person and not only a "What". The Holy Spirit is personal . . . sharing God's own love with us,
"in our hearts" >
"Now hope does not disappoint, because the love of God has been poured out in our hearts by the Holy Spirit who was given to us." (Romans 5:5)
I offer that, in order for the Holy Spirit to be the Spirit of God's own love, the Holy Spirit is a personal Being of God, not only a force. But humans may see love as being only a force; so they might "therefore" suppose the Holy Spirit is only a power or force. But God is personal, as the Father and Son and Holy Spirit > the Supreme Being of love which is family caring and sharing love.
And His love changes us so we relate personally as family with one another children of God > this is included in our basic calling >
"with all lowliness and gentleness, with longsuffering, bearing with one another in love," (Ephesians 4:2)
We can love any and all people, even, because it is no longer our nature to love only those we hope to use and whom we can possess (Matthew 5:46). And we can adopt ones who please to share with us in this loving, so that we are family with all others who have become changed like this.
Is there a big difference between Aristotelian and Leibnizian explications of entelechiae?
Possibly, Aristotle thought all is material and therefore entelechy is within the material realm with causes all physical somehow. But it seems Leibniz felt that there were non-material sources of effect on this world.
If all being is material, then the fulfilling results of all effects can be only material, just a rearranging of things, perhaps we could say.
But I understand that there is the spirit of evil > Ephesians 2:2 > which does effect physical things, but also effects a human's spiritual nature, using lusts to make a person want pleasure, and these lusts degrade a human to become
"worse and worse" (2 Timothy 3:13) in one's selfish nature . . . while one is going after material pleasures in order to feel better; but, "of course", while seeking material niceness for fulfillment, deeper the person is getting more and more ruined in one's character; because beneficial entelechy comes truly from God's love and not from making things nicer materially > the material can not change our spiritual nature.
So we need grace, which is the action in us of God's own almighty power of love, making us more and more like Him in love, while also making us creative spiritually and materially, so we can be involved in bringing out spiritual fulfillment beneficial and be creative with material things and enjoy (1 Timothy 6:17).
I'd like to understand better about entelechiae before subscribing to any philosophy.
I understand that there is, first, God Himself who is spiritual and almighty and love. Humans at our spiritual level are . . . nonmaterial, not controlled and decided by material forces, but we can be controlled by God in love, or by
"the spirit who now works in the sons of disobedience." (in Ephesians 2:2) So, this is part of why we need salvation . . . so God changes our nature so we become more and more immune to how Satanic things would effect us and control us.
By Satanic things I mean nasty angry reacting which is caring only or mainly about our own selves, versus how God's anger comes from love and brings a loving result creative, on the whole. And there are Satanic things of frustration, worry's abuse and pathological lying, unforgiveness, lingering hurts, bitterness, and being controlled by dictatorial lusts for pleasure in one's effort to feel something nicer than boredom and loneliness and confusion and other unloving things.
Only in God's love with power almighty can we be sweetly immune to such sin-sick stuff. So, this is part of why we need to be saved . . . so we are safe
from the abuse of Satan's selfish spirit. But, most of all, we get saved from God's judgment, but we become safe in His love which also makes us intimate and family with Him and one another.
This is not what comes with material entelechy, but only God is able to do this with us, and this is personal, in His love.
This is an interesting part of the discussion to me, Josef Pieper explicating Thomist theology writes that:
"Virtue is not the tame "respectability" and "uprightness" of the philistine but the enhancement of the human person in a way befitting his nature."
God changes our nature, so that we have what is befitting our new nature which is no longer human, but
"the divine nature" > 2 Peter 4:2. We do not just change from one human nature to another, by some virtue, but God changes our nature more and more into the nature of His own love >
"But he who is joined to the Lord is one spirit with Him." (1 Corinthians 6:17)
"Love has been perfected among us in this: that we may have boldness in the day of judgment; because as He is, so are we in this world." (1 John 4:17)
So, we are changed into a totally different nature which makes us able to be and live and share in God's totally different way of loving. We love because we personally care, among other benefits . . . while in our selfish loving as humans we often could fall in love with whoever made us feel good, in order that we would not feel, so much, that deep nasty mess of sin. Therefore, we used the ones we loved, not necessarily really caring about them. We could fall in love with what we wanted to use someone to get for our own selves; if we could not get it, we could have a falling-out!!
So, we tended to believe that material things could produce entelechy of what is desirable in us; however, material things can not produce good fulfillment or bad fulfillment which is spiritual in our spiritual nature. But a spiritual being can effect what is material, and materials can effect other materials. God can actually change the nature of a physical thing, including by the resurrection which makes our bodies spiritual and immortal and of His own glory . . . a major entelechy, to say the least.
"Theological virtue is an ennobling of man's nature that entirely surpasses what he "can be" of himself. Theological virtue is the steadfast orientation toward a fulfillment and a beatitude that are not "owed" to natural man. Theological virtue is the utmost degree of a supernatural potentiality for being. This supernatural potentiality for being is grounded in a real, grace filled participation in the divine nature, which comes to man through Christ." (2 Peter 1:4)
These quotes are from Pieper's book On Hope.
Ok, where he says "enabling of man's nature", at first I was thinking: no, God does not ennoble our human nature. But he seems to mean that God changes us from the human nature which we have had, into having God's own nature of love; and this is so better for our nature which is not longer human, but divine, making us able to love unselfishly and undesperately.
