Ephesians 6: Armor of God: Atack and defense

A Christians is a new creature - governed by Jesus who becomes a target of the evil forces, therefore he must resist its attacks:

13-18 Be prepared. You’re up against far more than you can handle on your own. Take all the help you can get, every weapon God has issued, so that when it’s all over but the shouting you’ll still be on your feet. Truth, righteousness, peace, faith, and salvation are more than words. Learn how to apply them. You’ll need them throughout your life. God’s Word is an indispensable weapon. In the same way, prayer is essential in this ongoing warfare. Pray hard and long. Pray for your brothers and sisters. Keep your eyes open. Keep each other’s spirits up so that no one falls behind or drops out.

Imagine a pastor who is calling many to Jesus. If he falls, he becomes a joke or a flag against Christians. Even if he doesn't fall, evil can lie and accuse therefore, it is imperative to pray hard and long and to live in community, in a church supporting each other.