Humans intuitively recognize free will as intrinsically good, both culturally and across time. This is relevant because, in the absense of defeaters, one rationally ought to believe in accordance with ones rational intuiton.
The ability to freely love in a genuine relationship with God is good. This is relevant because, among other things, it requires free will.
Many other states of affairs are good which also require free will,
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Note: although freely forming one's character is an intrinsic good, it is plausibly also good in virtue of being the means through which one can be reconciled with God. One might argue this way:
1. God desires to unite with us in loving fellowship; two wills integrated around the good.
2. But our hearts (and will) are wicked in a way that makes this impossible.
3. To fix this then, our hearts need fixing (in way which preserves our free will).
4. And this is best done is via a rescue operation where we make certain free self-forming choices, wherein we become progressively oriented towards the good.