It's the fault of the tempter and the one who yields to their temptation.
1Jesus said to his disciples: "Things that cause people to sin are bound to come, but woe to that person through whom they come. 2It would be better for him to be thrown into the sea with a millstone tied around his neck than for him to cause one of these little ones to sin. 3So watch yourselves.
"If your brother sins, rebuke him, and if he repents, forgive him. 4If he sins against you seven times in a day, and seven times comes back to you and says, 'I repent,' forgive him."
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13When tempted, no one should say, "God is tempting me." For God cannot be tempted by evil, nor does he tempt anyone; 14but each one is tempted when, by his own evil desire, he is dragged away and enticed. 15Then, after desire has conceived, it gives birth to sin; and sin, when it is full-grown, gives birth to death.