The devil has more temptations than an actor has costumes for the stage. And one of his all-time favorite disguises is that of a lying spirit, to abuse your tender heart with the worst news he can deliver—that you do not really love Jesus Christ and that you are only pretending, you are only deceiving yourself. (William Gurnall)
Satan is called in Scripture the Father of Lies (John 8:44). His very first attack against the human race was to lie to Eve and Adam about God, and where life is to be found, and what the consequences of certain actions would and would not be. He is a master at this. He suggests to us—as he suggested to Adam and Eve—some sort of idea or inclination or impression, and what he is seeking is a sort of "agreement" on our part. He's hoping we'll buy into whatever he's saying, offering, insinuating. Our first parents bought into it, and look what disaster came of it. The Evil One is still lying to us, seeking our agreement every single day.
Your heart is good. Your heart matters to God. Those are the two hardest things to hang on to. I'm serious—try it. Try to hold this up for even a day. My heart is good. My heart matters to God. You will be amazed at how much accusation you live under. You have an argument with your daughter on the way to school; as you drive off, you have a nagging sense of, Well, you really blew that one. If your heart agrees—Yeah, I really did—without taking the issue to Jesus, then the Enemy will try to go for more. You're always blowing it with her. Another agreement is made. It's true. I'm such a lousy parent. Keep this up and your whole day is tanked in about five minutes. The Enemy will take any small victory he can get. It moves from You did a bad thing to You are bad. After a while it just becomes a cloud we live under, accept as normal.