It is true that the OT did not teach much about the HS, but it said a lot about GW, which the NT indicates is essentially synonymous.
Thus, the questions is, "Did OT believers manifest godly fruit without having the HS or was the HS working without their knowledge?"
Here is my understanding of
Spiritual dynamics, referring to how God’s HS interacts and communicates/communes with humans.
It begins primitively when selfish but innocent babies attain the stage of moral accountability or conscience as they are able to understand what their parents deem to be right and wrong beliefs and behavior, which is normally well-developed by the age of eight or the stage of pre-pubescence, comparable to when Adam and Eve became aware it was wrong to eat from the forbidden tree (Gen. 2:17).
During this stage a soul’s
relationship with God begins when the person becomes a truthseeker (2Thes. 2:10), cf. Matt. 7:7, Heb. 11:6), because God’s Spirit is Truth (1John 5:6),
although the young soul may not realize it (Mark 12:33-34, Rom. 1:17). As a truthseeker at any time in history contemplates creation, Paul indicates that they will be able to discern God’s being and loving will in nature (Rom. 1:20, 2:14-15, Gal 5:14) by means of what theologians call general revelation. In this regard it is good to plumb the depths of Gen. 1:1-3 describing the Spirit of God’s presence as God spoke creation into existence and connect it with John 1:1-3 saying the Word was in the beginning and through Him all things were made (cf. Acts 17:27-28).
When truthseekers realize that God has a moral requirement,
if they worship Him they become like Abraham, and
the relationship with God becomes personal (Rom. 4:1-25). Presumably God provides such believers the opportunity to learn the proto-gospel, so they may repent of sin and accept the pre-incarnate foreshadowing of the sacrifice of Christ (cf. Gen. 3:21), whether in the form of Abraham’s ram (Gen. 22:13) or Moses’ lamb (Exo. 12:21). At the moment of worship and saving faith like Abraham,
the Spirit of Christ/God’s Holy Spirit enters the believer’s spiritual heart— again even though they may not realize it–because Paul taught that whoever does not have the Spirit of Christ does not belong to Christ (Rom. 8:9).
Paul referred to Abrahamic faith as spiritual circumcision (Rom. 2:29, 4:3-12). Of course,
partial knowledge of GW and spiritual dynamics will limit ability to cooperate with God, so there is a need for evangelism and learning the full Gospel (Matt. 28:19-20). For those who died as pre-NT believers, this must occur in heaven (cf. 1Pet. 4:6). Again, if a moralist truthseeker (on the basis of general revelation) encounters God (perhaps via the OT revelation), then he/she may believe or become a theist, like Abraham and Moses. If theists are taught the Gospel (NT revelation), then they may choose to believe/accept Jesus as Christ and receive the HS. In all cases salvation is a gift/grace from God received by faith “from first to last” (Rom. 1:17).
With greater awareness because of learning the NT Gospel, when a truthseeker confesses Jesus as Messiah and Lord (
Acts 20:21,
Rom. 10:9),
the HS indwells the convert’s heart (
Rom. 5:5) and unites him/her with God as heavenly Father (
Rom. 8:9)–which moment is called spiritual rebirth (
John 3:3-8), baptism by the Spirit (
Matt. 3:11/
Mark 1:8/
Luke 3:16,
John 1:33,
Acts 1:5,
1Cor. 12:13) and receiving the Spirit of adoption/sonship (
Rom. 8:14-16).
The outward evidence that someone was baptized by the HS (
Rom. 5:5) and is Spirit-filled (
Eph. 5:18) or walking with God is the fullness of Christ (
Eph. 3:19,
4:13) or fruit of the Spirit (
Gal. 5:22-23), which is
signified by “love” (
Gal. 5:6,
Matt. 22:37-40). Jesus said “All men will know that you are my disciples if you love one another” (
John 13:35,
1John 4:7-21), because divine love sums up the moral character of God (
1John 4:7-8).
There seems to be no reason not to think
these spiritual dynamics happened before the church age without people realizing it,
because these truths were not fully revealed.
Over...