4 His tail swept a third of the stars from the sky, tossing them to the earth. And the dragon stood before the woman who was about to give birth, ready to devour her child as soon as she gave birth. -Revelation 12:4 BSB
Lucifer (i.e., Satan the Adversary) deceived 33 percent of the angels in heaven, these deceived angels are known by many names, such as demons, fallen angels, evil spirits, unclean spirits, and legion, referring to when many demons possess a person all at once. Believers in Jesus Christ are overwhelmed by the number of the enemy. However, we have the upper hand, and the advantage is on our side. We have unlimited power through the indwelling of the Holy Spirit.
The only way that the enemy can defeat us is if we fall into sin. We must understand that demons are a real threat, and the only way that we can overcome them is by studying the Scriptures and doing what it says, period.