This is a comment by Greek scholar & popular author Bill Mounce:
"Is the subjunctive “shall” or “might”? (John 3:16)
I was asked about the subjunctive in John 3:16. The concern was that the NIV/NLT reads “shall,” which makes it a promise of salvation. His contention is that the subjunctive makes it a “condition of salvation” and it should be translated as “may,” and the Greek grammar does not “allow” the translation “shall.”
First of all, let’s have a little humility. To say that two major translations mistranslate a famous verse, choosing a translation that the Greek does not “allow,” is quite a claim.
Is it possible for two major translations to make a major mistake? Sure. I think that translating οὕτως in John 3:16 as “so” is precisely that. But is it possible that two major translations violate Greek grammar in the same verse? Highly unlikely.
Please people. Be very careful before claiming that major translations have chosen a translation that the Greek (or Hebrew) does not allow. You may disagree. You may not like it. But to claim that the translators violate Greek grammar requires too much hubris.
The NIV reads, “For God so loved the world that (ὥστε) he gave his one and only Son, that (ἵνα) whoever believes in him shall not perish (ἀπόληται) but have (ἔχῃ) eternal life.”
Why are ἀπόληται and ἔχῃ in the subjunctive? Is it because they are giving a “condition of salvation”? To be frank, I am not even sure what that means. Is there any question that if a person truly believes, he or she will truly be saved from perishing and will truly receive eternal life?
ἀπόληται and ἔχῃ are in the subjunctive because they are in a purpose clause. God sent his son for the purpose saving those who believe and for the purpose of bringing them safely to eternal life. Because purpose is not a statement of reality (indicative), it must be moved into the subjunctive.
The only remaining question is how to convey purpose in English. Some use “shall/will” (NIV, NLT, NASB, HCSB). Other translations use “should” (ESV, KJV) or “may” (NRSV,NJB). I don’t think there is any real difference in meaning.
Do you hear any difference?"
billmounce.com/monday-with- … -john-3-16
There are interesting comments following the above quote.