4 For it is impossible for those who were once enlightened, and have tasted the heavenly gift, and have become partakers of the Holy Spirit,
Those who revert to the Old Testament rites will tragically miss the glory of the supremacy of Christ’s sacrifice in forgiving sin. The person who does this will adopt doctrines that will blunt his maturity in Christ.
Verses 4–8 warn Christians about going astray theologically. These verses give a warning to Christians about reverting to the wrong solution, and verses 9–12 give them encouragement of hope.
The “for” here refers to God permitting us to move to maturity (He 6:3). Spiritual maturity is unattainable for those who fundamentally revert to the Old Testament rites for their understanding of Christ’s work (He 10:4).
it is impossible
Verses 4–6 form one sentence. The idea in this sentence is that it is impossible for those listed in these verses to experience true repentance if they revert to the type rather than the Antitype, the ongoing Levitical sacrifices rather than the final sacrifice of Christ. The issue is about the nature of this repentance; it is a repentance based on the work of Christ rather than the blood of bulls and goats. The writer clearly has Christians in view in these verses.
The sentence beginning with “it is impossible” finishes with verse 6. Impossible does not mean difficult. The same word is used three other times in Hebrews (He 6:18; 10:4; 11:6). This phrase governs the infinitive “to renew again” in verse 6. There are five descriptions of Christians (five aorist participles). Christians who revert to the Levitical sacrifices for their doctrine put themselves beyond the pale of New Testament living. As long as they use Levitical sacrifices rather than the final sacrifice of Christ, they cannot be renewed to repentance.
It is impossible for those who want to go back to the Old Testament economy to repent of their sins based on Levitical sacrifices. The reason is that they have turned to the wrong system of sacrifice. The old sacrificial system of the sacrifice of bulls and goats could not take away sin (He 9:11–15; 10:1–4). It was only the final sacrifice in Christ that could do this. It was impossible for them to recover spiritually if they reverted to the old economy.
for those who
The words “those who” are preceded by the definite article “the” in the original. The “the” here governs all five descriptions that follow (aorist participles). All five refer to Christians.
were once enlightened,
“Once enlightened” refers to those who have been exposed to the Christ of the New Testament (2 Co 4:3–6). “Enlightened” is also used of the readers’ initial response to the gospel (He 10:32). These people had seen for themselves who Jesus is.
Enlightenment occurred “once,” or at the one time in the past when they became Christians. “Once” means that it took place at one point. They never repeated the experience of salvation. Positional forgiveness never needs to be repeated. “Once” means once for all. The readers came to a given point of clear understanding of the gospel.
It is important to note here that God is the One who enlightened these believers (passive voice).
and have tasted the heavenly gift,
The word “tasted” conveys the idea of experiencing. These are believers who actually experienced the gift of salvation from Christ. The idea of “tasted” is to swallow. This was its usage in Hebrews 2:9, where Jesus experienced the full force of physical death.
and have become partakers of the Holy Spirit,
Note that the word “partakers” is used in Hebrews of Christians (He 1:9; 3:1, 14;12:8). The idea is to participate in. These believers had a close association with the Holy Spirit. They received Him into their lives.
Persistence in spiritual regression leads to an intransigent state in the Christian life.
It is impossible to move into maturity while holding false doctrine; it is not possible to mature without holding to right doctrine. If we inoculate ourselves with a false doctrine, we immunize ourselves against the truth. As long as we are immune from what God says, we will remain immature in our faith.