Num 23:19 God [is] not a man, that he should lie; neither the son of man, that he should repent: hath he said, and shall he not do [it]? or hath he spoken, and shall he not make it good? Tts 1:2 In hope of eternal life, which God, that cannot lie, promised before the world began; Hbr 6:18 That by two immutable things, in which [it was] impossible for God to lie, we might have a strong consolation, who have fled for refuge to lay hold upon the hope set before us: Have you ever considered why it is impossible for God to lie? I think Romans gives us a hint: Rom 4:17 (As it is written, I have made thee a father of many nations,) before him whom he believed, [even] God, who quickeneth the dead, and calleth those things which be not as though they were. Think of "God said let there be light, and there was light". If God has such creative power in his voice, it would literally be impossible for God to lie because whatever he said would BECOME truth because He said it. There wasn't light. God said - let there be light - and then there was light. If God can't lie because whatever he says becomes reality. Think about it -- if you pointed to an empty room and said "look, there is a dog" and a dog appeared, then you would quite literally be incapable of lying, wouldn't you?