Revelation 12:10 KJV
And I heard a loud voice saying in heaven, Now is come salvation, and strength, and the kingdom of our God, and the power of his Christ: for the accuser of our brethren is cast down, which accused them before our God day and night.
When we became followers of Christ, we also became an enemy to the devil. For this reason, satan is constantly looking for a way to oppose Christians. As we read in the above verse, he even accuses Christians before God day and night. This is one of the reasons why we should examine ourselves on a daily basis and be quick to repent for our sins. If we keep sin in our lives, satan is right there like an adversary in a court room to hold it against us. Thankfully, the Bible says of God: If we confess our sins, he is faithful and just and will forgive us our sins and purify us from all unrighteousness. (1 John 1:9) We can also pray and fast about our shortcomings so that Jesus can help us overcome them.
1 Peter 5:8-9 NIV
Be alert and of sober mind. Your enemy the devil prowls around like a roaring lion looking for someone to devour. Resist him, standing firm in the faith, because you know that the family of believers throughout the world is undergoing the same kind of sufferings.