In Romans 9, verses 22 and 23 comprises two parallel, though antithetical, statements that are constructed very differently from a grammatical and linguistic perspective. The use of two different words of similar meaning, the participle katertismena in v22 and the verb proetoimasen in v23, illustrates this point.
Romans 9:22-23 NKJV (parentheses added)
22 What if God, wanting to show His wrath and to make His power known,
endured with much longsuffering the vessels of wrath prepared
(kataritzo Strong’s 2675
meaning to complete, prepare) for destruction,
23 and that He might make known the riches of His glory on the vessels
of mercy, which He had prepared beforehand (proetoimazó Strong’s
4282 meaning to prepare before)
for glory
The OP asks, “What is the effect of proetoimasen being used in Romans 9:23?” The words appear synonymous in context; both are rendered with the word “prepared” in many English translations (e.g., ESV, NIV, NASB, NKJV) – katertismena as “prepared” and proetoimasen as “prepared beforehand.” Despite the similarity in meaning, the use of two different words serves to differentiate the action of katertismena from that of proetoimasen.
Rather than focusing on their definitions, I chose instead to examine the morphological differences between katertismena and proetoimasen, specifically the voice and tense inflections.
VOICE: Active vs. Passive (or is it Middle?)
Based on the interlinear of Rom 9:22, the voice of katertismena can be either middle or passive.
the vessels of wrath prepared (katertismena Verb - Perfect Middle/Passive
Participle) for destruction
Vine’s Expository Dictionary interprets katertismena to be middle, meaning that the subject is both the agent and the recipient/experiencer of a verbal action (Voice: Middle). However, according to Daniel Wallace, to interpret katertismena as middle is contrary to the normal use of a perfect participle (Basics of New Testament Syntax, p.183). That katertismena is middle is therefore not certain, but I do prefer Vine’s definition of katertismena and have included it below for reference.
Vine’s Expository Dictionary
"to make fit, to equip, prepare" (kata, "down," artos, "a joint"), is
rendered "fitted" in Rom 9:22, of vessels of wrath; here the Middle
Voice signifies that those referred to "fitted" themselves for
destruction
Thayer’s Greek Lexicon, on the other hand, identifies the voice of katertismena to be passive with God as the agent of the action.
Thayer’s Greek Lexicon
of men whose souls God has so constituted that they cannot escape
destruction (but see Meyer (edited by Weiss) in the place cited),
Romans 9:22
Even if we allow that katertismena is passive, Thayer’s interpretation is problematic. First, the participial construction is ambiguous with regard to the identity of the agent. Second, there is no mention of souls in the text, and the concept of “vessels” itself suggests that “souls” is not implied.
Barnes Commentary on Romans 9:22
In this place there is not the semblance of a declaration that "God
had prepared them, or fitted them for destruction." It is a simple
declaration that they were in fact suited for it, without making an
affirmation about the manner in which they became so.
In contrast to the ambiguity of v22, God is the subject of proetoimasen in v23 and, given the active voice, is the express agent of the action. Also worth noting is that of the only two occurrences of proetoimazó in the NT (Rom 9:23 and Eph 2:10), God is the subject/agent in both.
the vessels of mercy, which He had prepared beforehand (proetoimazó Verb - Aorist
Indicative Active) for glory
TENSE: Aorist vs. Perfect Participle
Whereas the verb proetoimasen is in the aorist, the participle katertismena is in the perfect tense. In addition to their voice inflections, the difference in tense further distinguishes the actions of these verbs. The perfect participle signifies that while the action of katertismena occurred in the past relative to the action of the main verb, there is an ongoing effect that continues in the present. (Greek Verbs: The Perfect Tense).
The verb proetoimasen, on the other hand, is in the aorist tense, indicative mood. When the aorist is paired with the indicative, it means that the action of the verb occurred in the past in an absolute sense. In other moods, the aorist indicates aspect rather than time. As a general rule, “Only in the indicative mood does the aorist indicate past time” (Greek Verb Tenses).
The “pro” in proetoimasen, meaning beforehand, underscores the fact that the action occurred in past time. The OP asks, “Before what?” Because of the complex sentence structure, it is difficult to answer this question. That said, the “pro”/beforehand suggests that the action of proetoimasen came before those of all the other temporal verbs in vv22-23.
CONCLUSIONS
Another important question is whether the vessels of wrath are distinct from the vessels of mercy. If the vessels of wrath and the vessels of mercy are two distinct groups, then it stands to reason that all the vessels cannot belong to any one group. Yet every person without exception is said to have sinned and fallen short of God’s glory (cf Rom 3:9-10, Rom 3:22-23, Rom 5:12, Rom 11:32). To consider them as entirely separate groups is, I believe, contrary to one of the main themes of Romans, which is that God does not show favoritism (cf Rom 2:11, Rom 10:12-13).
Romans 11:32
For God has committed them all to disobedience, that He might have
mercy on all.
There is a play on words in the imagery of the vessels. Vessels have both an outside and an inside, the container and what it contains. Men are vessels fitted for wrath; in other words, sin is inherent to our nature (Ro 6:6, 7:23-24). But it is man himself who, in bringing sin into the world, has prepared himself for destruction.
Romans 5:12
Therefore, just as through one man sin entered the world, and death
through sin, and thus death spread to all men, because all sinned
But God prepared beforehand for us to become vessels of mercy, that is, vessels capable of holding a spirit and a righteousness that is not our own.
Romans 8:9-10
9 But you are not in the flesh but in the Spirit, if indeed the Spirit
of God dwells in you. Now if anyone does not have the Spirit of
Christ, he is not His. 10 And if Christ is in you, the body is dead
because of sin, but the Spirit is life because of righteousness.
2 Corinthians 4:7
But we have this treasure in earthen vessels, that the excellence of
the power may be of God and not of us.
While some questions remain unanswered, Rom 9:22-23 tells us that God planted the seed of our redemption, knowing we would sin. He prepared us for mercy, we who were fitted for sin, who even now may be preparing ourselves for destruction (cf Rom 2:5). While the word proetoimasen may reference a past action, it also anticipates an event that is to come.
Thus another way to conceptualize the OP’s question (“Before what?”) is by asking: For what has God prepared us? Using proetoimasen as a bridge between Rom 9:23 and Eph 2:10, that event is understood to be our rebirth in Christ (cf Rom 6:4, 6:11; 7:5-6). God made us from clay, knowing our natural limitations (cf Ps 103:14). But He also prepared us for great things, even to be through Christ a dwelling place of God.
Ephesians 2:10
For we are His workmanship, created in Christ Jesus for good works,
which God prepared beforehand that we should walk in them.
