This post contains what some may consider to be "severely disturbing" content. Please read with care and caution.
As a boy growing up in Sunday School, I was made aware of a fallen angel by the name of Lucifer. He was an archangel like Michael and Gabriel, and was put in charge of worship.
Because he rose up against God, he and a third of the angels were banished from heaven, and is now behind the evil that is going on in the world. The tsunami, 911, SARS, earthquakes and cyclones are the works of his hands. He is described in Jn 10:10 as the thief who comes to steal, kill and destroy.
This is a bad situation for those not under the New Covenant, as there is no protection for them to begin with. Because Adam had forfeited to him the God-given authority to subdue the earth, he has free reign to do to mankind as he pleases.
The good news for us New Covenant believers is that we have the shed blood of Jesus Christ to protect us from harm, curses and diseases.
So why is it that many of us still struggle, and do not experience the victorious, abundant zoe life that is rightfully ours?

Lucifer is also referred to in the Bible as the "devil". The Greek word for "devil" is diabolos (διάβολος), from which we derive the English word diabolical. While this is used to describe something that is extremely evil or cruel, what is interesting is that the Greek word itself actually means a "slanderer" or "false accuser".
And that is primarily what he does to the New Covenant believer, that prevents us from living that victorious life!
He falsely accuses us, makes us sin-conscious and distracts us from being Jesus-conscious and what the finished work has accomplished for us.
For example, let's say we are driving to church one Sunday morning, and someone suddenly cuts in front of our car. In anger, an expletive comes out from our mouth. After that happens, we start feeling guilty and we hear a voice saying, "Call yourself a Christian. Can't even exercise patience and self-control. Use bad words some more. On your way to church to worship God? Such a hypocrite." When we dwell on those words of condemnation, we feel lousy and are in no mood to worship God, and what results is that the entire church service is ruined. The devil has just succeeded in stealing the joy of being in the presence of the Lord with the company of believers.
And that is why John describes him as "the accuser of the brethren" in Rev 12:10.
But what weapon does the devil use to accuse us with? The irony is that the devil uses God's very own Laws as that weapon!!!
Picture a courtroom with us as the defendent, God as the judge and the devil as the prosecutor. The devil will present the case to God saying,"Your Honour. The defendent was found to be using an expletive and losing his temper. His behaviour is unbecoming of a Christian. I say he be punished to the full extent of the law, the law that you have prescribed."
Picture now another lawyer* stepping up to take the stand before the judge, and telling him, "Yes your Honour. My client has indeed broken Your law. However, I have already taken upon myself the punishment for this, as well as every single other breach of the law ever committed and ever to be committed, some 2000 years ago."
To which the judge replies, "Justice has already been served, and the law of double jeopardy dictates that I cannot punish the same crime twice. You are free to go. Case dismissed!"
*Jesus is described in 1 Jn 2:1 as our advocate (a lawyer who pleads in a court of law on our behalf).
And so coming back to the earlier example. Instead of giving in to the devil's accusations and dwelling on those words of condemnation, we instead tell him," Yes, I blew it, but Rom 8:1 tells me that there is now no more condemnation in Christ Jesus. I confess that sin of anger in that I agree with God's Word that tells me that Jesus has taken the judgement of all my sins, past present and future upon His own body on the cross. As such, I can go to church and worship Him knowing full well that I stand before Him blameless as the righteousness of God in Christ."
When we are Jesus-conscious, the devil is disarmed and defanged. He may go about as a roaring lion to seek whom he may devour (1 Pet 5:8), but we remain undevourable because we rest in the finished work. Amen?