The most simple answer I have ever heard to this question is God cannot act outside His nature. Sinning has nothing to do with God's power, but His character. He is a holy and perfect in all His ways. To sin is to violate that character.

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J Baldwin
Keowee Presbyterian Church, PCA
Pickens, SC
“You shall love the Lord your God with all your heart and with all your soul and with all your strength and with all your mind, and your neighbor as yourself.” Luke 10:27

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