Rejecting, Quenching, Grieving
According to Trinitarian theology, a person who denies Christ's deity and by extension the personhood of the Holy Spirit (the Spirit of Jesus Christ), is by definition a Non-Christian. I think a better terminology would be "rejecting" (due to lack of faith), just as the Pharisees rejected the claim that Jesus came from God to save humanity, labeling Him instead as a false messiah, or a false prophet. A born-again Christian will have the true Holy Spirit testifying in that person's heart that Jesus is God. A born-again Christian will also see the Holy Spirit as a person (in fact, the spirit of Jesus) who wants to reside in his / her heart, leading one's life to the fullness of salvation and life's potential.
In this theology, quenching and grieving are what Christians do (or at least those who think they are born-again), leading them toward apostasy. The best scenario is that they will repent, which I think is the intent of Paul when using the words in his letters, since the audience is Christians.
Therefore, to understand what the words mean in the original Biblical context, we need to pay attention to how Paul use them:
"Quenching the Spirit" (as used in 1 Thess 5:16-22) is about refusing/despising some gift/fruit GIVEN BY the Holy Spirit. In Pentecostalism, this is often used against Cessationists. But as both John Piper's interview Am I Quenching the Holy Spirit? and your gotquestion.org article explain, the gift referred to by the passage should not be limited to Pentecostal-specific giftsbut also include the fundamental gift of the Holy Spirit's working out the new life within us. John Piper gives 4 examples of quenching the spirit:
- Despising some gift of the Holy Spirit. Instead, test everything and hold fast to what is good.
- Neglecting some gift that we have. Instead, fan it into flame.
- Shutting down our emotions and refusing to give expression to them. Instead, follow the promptings toward singing and other joyful expressions.
- Resisting the fruit of the Spirit in our lives. Instead, obey the exhortations live out the fruit of the Holy Spirit.
In contrast, "grieving the Holy Spirit" (as used in Eph 4:17-32) seems to have more to do with OUR immoral behavior after being saved, reverting to our fleshy old life before being born again. A Christianity.com article What Does It Mean to “Grieve the Holy Spirit”? lists 6 examples:
- Foul and abusive language makes the Holy Spirit sad. Instead: be authentically godly.
- Bitterness makes the Holy Spirit sad and sorrowful. Instead: forgive.
- Fits of rage and uncontrolled anger make the Holy Spirit sad and sorrowful. Instead, ask yourself, is it T.H.I.N.K. (Truthful, Helpful, Inspiring, Necessary, Kind)?
- Blocking the Spirit's being a light to us in three ways:
- Exposing our guilt. Instead, we grieve the Holy Spirit when we use him to excuse our sinfulness.
- Illuminating the Word of God. Instead, we grieve the Holy Spirit when we pit him against the Scriptures.
- Showing us Christ. Instead, we grieve the Holy Spirit when we suggest he is jealous of our focus on Christ.
Answering your question
Your question conflates 2 issues: faith and experiencing new life to the full. We all need to have faith FIRST, and then as a response to grace we have the responsibility to keep choosing to live worthy of the new spiritual life we have been given. Quenching/grieving the Spirit doesn't make sense until we have faith, because prior to faith there was no new life to begin with (there was no Holy Spirit living in us yet).
And yes, of course, if born-again Christians keep rejecting the Holy Spirit's work in them, they are either deluding ourselves that they are Christians, or they are trampling on the blood of Christ by refusing to cooperate with the Holy Spirit work in them. And yes, by quenching & grieving the Holy Spirit, how can he renews and perfects our lives so we can live to our full potential, the way God intends them to live?
Finally, let's be careful by the term "fullness of the Spirit" (Eph 5:18) and again, look in the larger context of Eph 5:1-21. Not all Trinitarians are Pentecostals/Charismatics. A Reformed understanding of this verse doesn't include Pentecostal-specific spiritual gifts (e.g., glossolalia), as explained in John Piper's sermon on Eph 5:18: Be Filled with the Spirit in which he contrasts this command with Pentecostals' interpretation of the verse as a command to be baptized with the Spirit.
Extra Credit: Practical consequences of a Trinitarian theology
For an excellent presentation of how essential Trinitarian theology is to a practical life of faith, please read Gary Deddo's paper The realist and onto-relational frame of T. F. Torrance’s Incarnational and Trinitarian theology which introduces the two recently published posthumous works by an evangelical Reformed scholar T.F. Torrance, who is believed to be the second-greatest Reformed Protestant theologian in the 20th century after his mentor Karl Barth:
It is almost a truism to say that Torrance’s theology is incarnational and Trinitarian, so central were these two foci to his entire theological work. What is perhaps not as readily recognized is that this incarnational and Trinitarian theology takes place within a surrounding two-dimensional framework that can be identified as realist and onto-relational. Gary Deddo argues that these two aspects are essential to understanding Torrance’s framework for pursuing the theological task. After exploring these themes theologically he considers their implications for practical theology and for Christian ministry.
Answering a follow-up question
Very interesting thoughts, but I'm unsure if you have answered the main question. Are you suggesting that non-trinitarians do not even have faith nor the Holy Spirit to begin with?
I'm not arrogant enough to claim that I know what God, in His omniscience, knows what is going on in someone's heart, whether they are a professed non-Trinitarian or a Trinitarian like myself. However, we are talking theology here, which is a conceptual framework, a human construction, aided by the work of the Holy Spirit within a community that produces the framework of Trinitarian orthodoxy). You will need to be very careful whether you're talking about the former or the latter.
My answer presupposes the latter (i.e., a conceptual framework), in which a faith that is based on a Jesus who is not Divine is not saving faith and does not produce a spiritual life with the attendant presence of the Holy Spirit within true Christians. With no Holy Spirit, there is no one to grieve or quench. But who am I to judge whether a non-Trinitarian really has no Holy Spirit in them when many cultural Trinitarian Christians who claim to have faith may in the end mot have it? Even the Puritans, who were Trinitarians, were conscious of the link between the fruits of their faith, on the one hand, and the assurance of having real faith, on the other.
Again, knowing who is saved and who is not is a prerogative of God alone.
Additionally, faith is more than merely holding a number of propositions in one's mind. I personally believe that one can have a bad theology (such as non-Trinitarian or LDS or JW) but still be saved (although I cannot be certain because I'm not omniscient). If someone were to ask me about what real faith is, I could answer only within a conceptual framework and say that what's critical to real faith is hating sin and wanting the Holy Spirit to transform one's life to serve God and worship Jesus. This desire, an act of the will, is borne from genuine faith that is accompanied by emotion. Sooner or later, however, the mind needs to be involved so that one's understanding of the faith reflects accurately who God really is, what He has done, and how He relates to us NOW.
What feeds this understanding? Orthodox theology. What is its primary function? To guard us against errors and bad Christian practices that misrepresent the true nature of God and the true nature of Christian salvation and life. A Christian's failure to apply the Trinitarian answer to the way they live their life is useless.
Hypothetically, if a person is convicted of sin by hearing a presentation in a Mormon context and subsequently puts their newfound faith into practice, then perhaps they are truly Christain.!
Answering another follow-up question
When you say you are not sure whether or not a non-Trinitarian has the Holy Spirit, aren't you essentially saying that you are not sure the Trinitarian framework is true? If, however, the Trinitarian framework is true, and you are completely confident in it, then you should also be completely convinced that non-Trinitarians do not have the Holy Spirit.
We have to differentiate between trust in God and trust in a theological framework. The former is trust in a living Being, whereas the latter is trust in a framework that leads one to God. Only God is going to judge whether someone has responded well to the gift of new life and to the Holy Spirit's leading. Even I cannot claim with absolute certainty that my faith in God is genuine, since faith itself is a gift from God!
While I have chosen the Trinitarian framework to lead me to trust the one true God, that trust is different from the God-given faith to trust God. Presently I have complete confidence in this framework. That confidence, however, does not apply to whether or not I believe non-Trinitarians have the Holy Spirit, because as I said above, faith is a gift from God to individuals. What if God gives the Holy Spirit to a non-Trinitarian, knowing they are deluded, but also knowing they will eventually become Trinitarian?
As I explained earlier, it's the whole heart response that matters, not simply one's recitation of the Nicene creed, for example. If a non-Trinitarian serves God, repents of their sins, and is conscientious not to quench or grieve the Holy Spirit God, perhaps their defective understanding of God may be less important in the eyes of God, than the defective thinking of someone with the "correct" theology but who nevertheless divorces their heart from their mind.
What a Trinitarian theology does is to "plow the mind's soil," so that when God implants faith in a Trinitarian's heart, the soil has the potential to bear more fruit than it does in the mind of a non-Trinitarian. In either case, a person's cooperation causes their potential to become a reality.
I think Paul's instruction about eating food offered to idols (1 Cor 8-10) illustrates my point quite well. Paul recognized a division among the Corinthian Christians. Those who believed that eating meat offered to idols was NOT okay, and those who believe it was. I find Paul's conclusion (1 Cor 10:31) surprising, since instead of rebuking the ones who believe it's not okay to eat meat sacrificed to idols, he realizes their belief comes from their reverence for God and is a lifetime habit that cannot be changed overnight. Paul's conclusion: "Whatever you do, do it all for the glory of God." Similarly, although Trinitarian theology says that faith requires belief in the Trinitarian conception of God (Paul saying in 1 Cor 25 that "So you may eat any meat that is sold in the marketplace without raising questions of conscience") who can restrict God's freedom to give faith and Holy Spirit to whomever He chooses, even a non-Trinitarian, provided that person is really seeking God, but out of reverence for the oneness of God has a hard time believing fully in Trinitarian theology?