Why would a married pastor have sexual relations with a member of his church? Why would a priest molest a small boy? Its called choice, what some would call free will, others would call permissive will. It seems to be something that Calvinists deny.
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Luk_8:10 he said, "To you it has been given to know the secrets of the kingdom of God, but for others they are in parables, so that 'seeing they may not see, and hearing they may not understand.'
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1Co_1:27 But God chose what is foolish in the world to shame the wise; God chose what is weak in the world to shame the strong;