It seems to be a common idea among Christians to blame the devil for their thought life, and thus the words or actions produced by their thoughts, but the Scripture does not agree with this belief at all.
What this idea amounts to is a feeble attempt to transfer blame - if we are not the one to blame, we are not really responsible, therefore can not be held accountable...
Just to elaborate on what Stephen said...
Jer 17:9 The heart is a twisted thing, not to be searched out by man: who is able to have knowledge of it?
Jer 17:10 I the Lord am the searcher of the heart, the tester of the thoughts, so that I may give to every man the reward of his ways, in keeping with the fruit of his doings...
Jer 17:14 Make me well, O Lord, and I will be well; be my saviour, and I will be safe: for you are my hope.
Mat 12:33 "To have good fruit you must have a healthy tree; if you have a poor tree, you will have bad fruit. A tree is known by the kind of fruit it bears.
Mat 12:34 You snakes---how can you say good things when you are evil? For the mouth speaks what the heart is full of.
Mat 12:35 A good person brings good things out of a treasure of good things; a bad person brings bad things out of a treasure of bad things.
Luk 6:45 A good person brings good out of the treasure of good things in his heart; a bad person brings bad out of his treasure of bad things. For the mouth speaks what the heart is full of.
2Co 4:6 The God who said, "Out of darkness the light shall shine!" is the same God who made his light shine in our hearts, to bring us the knowledge of God's glory shining in the face of Christ.
2Co 4:7 Yet we who have this spiritual treasure are like common clay pots, in order to show that the supreme power belongs to God, not to us.
