We cannot make "fallen away" or "gone astray" as losing a gift that was freely given to us......in the passive voice.
The author is laying out our proleptic position in Christ. We have a position and condition. And in our condition we use positive volition to grow experientially while we are alive. We can mature in Christ or we can stay a babe.......our choice.
So what is the going astray or "fallen away?" The author is pointing out that these believers have fallen away from their growth or experience in Christ. Not that they have fallen away from the gift of salvation.
"for those who"~~~Reversionists. Going back to legalism in this case. the direct object.
"once received illumination"~~PASSIVE voice and culminative Aorist..........Position in Christ.The righteousness of God.
"having begun to taste (for themselves) the gracious gift of heaven"......Middle voice and ingressive aorist. Fellowship with Christ requires positive volition on the believers part..............Experiential state or position.
"having been made partners with the Holy Spirit".......PASSIVE voice and culminative aorist. ........Position in Christ.The righteousness of God.
"having begun to taste(for themselves) the good word of God".....Middle voice,ingressive aorist....The believer must have positive volition towards doctrine. Experiential state or position.
"having begun to taste(for themselves) the miraculous powers of the age to come"....middle voice,ingressive aorist.....Experiential state or position.
"but afterwards going astray" Active voice, constative aorist........The believer rejects Gods plan......Experiential state or position.
And as long as the believer stays in this state of reversionism, it is impossible to restore them to a change of mind in their experiential state or position.
They are safe in their Position in Christ, but they are LOSERS in the experiential state. And they are CLOSE to being cursed in their experiential state. But in their position in Christ they are safe.
1 Cor 3:15~~
New American Standard Bible
If any man's work is burned up, he will suffer loss; but he himself will be saved, yet so as through fire.