DEVIL SPEAKS TRUTH

I've done it, and it's been done to me. Someone - 'with malice in their heart' (Ps 5) - will say something 'true', so that you will get caught up in your own lie.
 
For example, smiling, half in jest whole in earnest, the jealous man says to you, 'You don't deserve that new car!' You feel the dark cloud descending on an otherwise sunny day, and you scramble to save the sunshine; you say, 'The year I've had, I do deserve this!'
 
Proverbs 26:4 tells us to not answer a fool according to his folly, 'lest you become like him.' What happened in above scenario is the fool spoke 'truth': you don't deserve it; we don't deserve anything. We should never speak on this level about anything we have, or anything others have.
 
Paul writes in Corinthians, 'What do you have that you have not been given? And if you have been given it, why do act as if you have not?'
(1 Corinthians 4:7)
 
Perhaps the most extreme example of the deepest truth masking the deepest lie, is when the devil himself speaks 'truth' to Jesus. Jesus, weary and hungry, is approached by the devil and challenged. The devil tests him not by lying, which is his native tongue (John 8:44), but by the other extreme of his strategies, i.e. dressing to look like 'an angel of light'. (2 Cor 11:14)
 
The devil quotes the bible to Jesus, and, on the surface, correctly. He quotes Psalm 91:11-12, messianic Scriptures to the Messiah. You can read about this exchange in Matthew 4:1-11. Note, when Jesus had so purely walked in wisdom, and the Spirit of truth, the devil shows his true motive – which was for Jesus to worship him, the devil. (Mt 4:9) We won't unpack it here, but suffice to say, truth is not 'word-deep'. Truth is spirit, and words - even words from the Bible - can be a cloak of malice.