John 8 vs 44

“When he lies, he speaks according to his own nature, for he is a liar and the father of lies”

The first time Satan appears in the Bible in Genesis 3, the first words on his lips are suspicious of the truth (“Did God say, You shall not eat of any tree in the garden?”). And the second words on his lips were a subtle falsehood (“You will not die”).
John says that Satan “has nothing to do with the truth, because there is no truth in him”.
We are dealing with the essence of falsehood and deception.

But, God intends that part of our preparation for heaven be a life of warfare with this liar, and all of hell. He calls it a “good warfare” and a “good fight” as seen in 1 Timothy 6:12. It is good, not because we might be killed (which we might! — Revelation 2:10), but because these fire-fights refine the gold of our faith, in life and death.
It makes us get closer to God, even though the devil wanted otherwise.

God is the great General in this warfare. He has given us the walkie-talkie of prayer to call for help. He said in His word, “Take . . . the sword of the Spirit, which is the word of God, praying at all times”

He sees behind enemy lines, and knows exactly the strategies that will be used against us. He has written them down in a wartime manual “so that we would not be outwitted by Satan.” The reason we will not be outwitted is that “we are not ignorant of his designs”. We refuse to be caught off guard.