Agree with "cut the Gordian knot" answers recommending you change your lead-in to the quote so you don't have to change the quote. The problem with that solution is that you can't always do it. So we're back to your original question.
If this is a scholarly essay/paper for a class/journal, then AFAIK you should use , regardless of how ugly or distracting it is, because  is the standard notation among scholars. Bracket the whole word, or bracket where the missing letter(s) would be.
If this is non-scholarly, then you have another option. In many English translations of the Bible, italic font is used for words which were not explicitly in the original Greek/Hebrew/Aramaic, but which the translators felt were clearly implied and necessary for smooth flow in English. You could use that technique on the changed word. Italics has the advantage of being less intrusive than , but the disadvantage that some readers might think the word isn't in the original at all. However, if you MUST change a quoted holy text, then you MUST indicate that somehow, consequences be darned.
(If you were adding a single letter, you could make that one letter italic. Sure, it would be hard to notice, but you're not changing the meaning so you're only obligated to obey the LETTER of the law. yukyukyuk)