You can read my three previous posts on this issue here, here and here. I last left this discussion having arrived (very tentatively) at the following conclusions: first, and never really in doubt during discussion, salvation was always by faith alone. Second, regeneration was always necessary to counter Total Depravity in both the OT and NT. Third, there appeared to be a distinction between the Spirit 'on' individuals in the OT and the Spirit 'in' believers in the NT (broadly speaking). The mechanics of how this all held together was left unclear.
I was (relatively) OK with this broad position until a recent discussion pointed out 1 Peter 1:10-11:
Concerning this salvation, the prophets who prophesied about the grace that was to be yours searched and enquired carefully, enquiring what person or time the Spirit of Christ in them was indicating when he predicted the sufferings of Christ and the subsequent glories.This verse appears to suggest the prophets had the Spirit of Christ indwelling their hearts prior to the coming of the Spirit himself. This sent me back to the issue for a reappraisal. Here are some further (still tentative) thoughts on this topic.
Before I go on, it's important to affirm what I uphold. Principally, I maintain salvation - in both OT and NT - was by faith alone. Similarly, I maintain the Reformed ordo salutis that Total Depravity demands regeneration by the Spirit prior to conversion. However, I want to uphold a legitimate distinction between Christ's going and the Spirit's coming. I also want to maintain a reasonable distinction between Ezekiel's comment (related to a future reality) and the present experience, at the time of writing, of OT believers.
In previous discussions, I posited the idea the Spirit may not necessarily have indwelt OT believers (though they were regenerate). The question follows: is it possible to have regeneration without indwelling? Certainly, the ordo salutis would allow for this. Further, there is no scriptural reason to insist - just because the Holy Spirit indwells believers as a sign and seal of their faith today - that excludes God's work on unbelievers prior to faith. Even in the church age, where we certainly receive the indwelling Holy Spirit, we believe regeneration occurs prior to conversion from which indwelling follows. Indeed, John 16:8-11, Titus 3:5 and James 1:18 would bear this reading out. If such is true, we have good grounds to argue regeneration occurs without indwelling (though receipt of the Spirit follows for believers today). If it is true that regeneration occurs prior to indwelling, this could readily apply to OT regeneration irrespective of their indwelling.
Given that, Jesus words in John 14:16-17 would also bear out this reading:
I will ask the Father, and he will give you another Helper, to be with you for ever, even the Spirit of truth, whom the world cannot receive, because it neither sees him nor knows him. You know him, for he dwells with you and will be in you.Notice Jesus' construction here. His disciples know the Spirit because he dwells, or abides, with you (present tense) but he will be in you (future tense). As John Hendryx helpfully points out:
This is a future tense of an indwelling. Apparently the saints of the OT enjoyed regeneration but may not have enjoyed indwelling... Regeneration and indwelling are not exactly the same for in regeneration the Spirit works to illumine our minds and renew our hearts prior to our faith in which He comes to indwell us. That pre-salvific action is not called indwelling. "WITH YOU" and "IN YOU" appear to demonstrate qualitative differences.So, just as the OT believing Jews experienced a type and shadow of things to come, so it may be they were regenerate - that is the Spirit worked on the hearts and minds of OT believers - without indwelling their hearts. Today, the ordo salutis is largely logical (not necessarily sequential). That is, regeneration is logically prior to conversion which is logically prior to indwelling and sanctification though the latter three (broadly) occur simultaneously and end in glorification. For the OT believer, the same logical sequence would be true but regeneration and conversion happen in quick succession, whereas indwelling, sanctification and glorification may all occur later in a much more rapid succession.
There is an argument that OT believers were both regenerate and indwelt by the Spirit. Yet, this quashes any meaningful difference, as outlined in Ezekiel 36 and John 16, pre- and post- the Spirit's coming. It is often argued the difference was between a partial experience of the Spirit and the fullness after his coming, the emphasis falling upon Joel 2:28-29 and the post-Pentecost signs and wonders. However, it can't escape our notice that such things also happened in the OT. Visions and dreams were experienced and miraculous works were done as well. This doesn't really provide us with any quantitative or qualitative difference.
How then do we explain OT believers doing miraculous works and specific tasks? It seems, in the OT, the Spirit came upon people and anointed them selectively and temporarily for particular works (cf. Judges 15:14; 1 Samuel 16:12f; 2 Chronicles 20:14; et al). It is notable that the Spirit of the Lord came upon Saul (1 Samuel 10:10) and yet he is widely regarded to have died in unbelief. As such, the Spirit coming upon an individual did not necessarily indicate their spiritual state. The Spirit thus moved individuals to specific acts without necessarily indwelling. Again, such causes a problem for the view that Pentecost was the dawn of the fullness of the Spirit's coming (these acts of the Spirit were occurring in the OT).
How then do we explain verses such as Numbers 27:18; Ezekiel 2:2; 3:24; Micah 3:8; Luke 1:15, 41, 67; 1 Peter 1:10f? They are best understood as the Spirit moving these individuals at particular times for particular tasks. So, the prophets who enquired "what person or time the Spirit of Christ in them was indicating" could be read less as a reference to their ongoing, permanent indwelling and more a reference to the empowering of the Spirit at the point they were prophesying. In other words, this is a manifestation of the selective, temporary anointing of the Spirit. It does not speak to permanent indwelling but their anointing by the Spirit as prophets, spokesmen for God, whom the Spirit also anointed to write the canon.
This reading allows us to make a qualitative difference between the pre- and post- coming of the Spirit. It stops us from quashing all meaningful difference in the words of Ezekiel and Jesus. It also allows us to uphold Paul's statements in Romans that the Spirit - the same Spirit who descended on Jesus, anointed him at his baptism and on whom he relied to live out a perfect human life - will empower us to keep God's law in a way OT believers could/did not. This reading maintains the continuity of Covenant Theology - salvation by faith alone requiring the regeneration of the Spirit of God to overcome our Total Depravity - without flattening any sense of discontinuity from when the Spirit begins to dwell in the hearts of God's people.