Our defense is provided by the Full Armor of God found in Ephesians 6. I would recommend this article: https://www.gotquestions.org/full-armor-of-God.html
(I also want to recommend the YouVersion Bible App for your smart phones or computers. Good studies there on the Full Armor of God)
Here’s a quote: “In verse 18, we are told to pray in the Spirit (that is, with the mind of Christ, with His heart and His priorities) in addition to wearing the full armor of God. We cannot neglect prayer, as it is the means by which we draw spiritual strength from God. Without prayer, without reliance upon God, our efforts at spiritual warfare are empty and futile. The full armor of God—truth, righteousness, the gospel, faith, salvation, the Word of God, and prayer—are the tools God has given us, through which we can be spiritually victorious. Satan is a defeated foe.”