We live in a world of deceit, and we are greatly pressured to conform to deceitful things, which is why Scripture tells us to “not conform to the pattern of this world” (Rom 12:2). When the Bible says that Satan is the “god of this age,” it is not saying that he has ultimate authority. It is conveying the idea that Satan rules over the unbelieving world in a specific way: “The god of this age has blinded the minds of unbelievers, so that they cannot see the light of the gospel that displays the glory of Christ, who is the image of God.” (2 Cor. 4:4)   In John’s day there were teachers going about performing certain signs, perhaps giving predictions of things to come or manifesting tongues, miracles, and other such things. And we still see those today.

It is of this that John writes and says, “Dear friends, do not believe every spirit, but test the spirits to see whether they are from God, because many false prophets have gone out into the world.” (1 John 4:1) Satan is also called the “ruler of the kingdom of the air” (Eph. 2:2) and the “the prince of this world” (John 12:31). These titles and many more signify Satan’s capabilities, signifying that in some way he rules over the world and the people in it, but not completely; God is still sovereign.

But it does mean that God, in His infinite wisdom, has allowed Satan to operate in this world within the boundaries God has set for him. When the Bible says Satan has power over the world, we must remember that God has given him domain over unbelievers only. Believers are no longer under the rule of Satan (Col. 1:13). Unbelievers, on the other hand, are caught in “the trap of the devil” (2 Tim. 2:26), are “under the control of the evil one” (1 John 5:19), and are in bondage to Satan (Eph. 2:2).

Satan’s scheme includes promoting false philosophies in the world—philosophies that blind the unbeliever to the truth of the Gospel. Satan’s philosophies are the fortresses in which people are imprisoned, and they must be set free by Christ. Jesus cautioned us “Watch out that no one deceives you.” (Matt. 24:4) Paul reminds us “This is how you can recognize the Spirit of God: Every spirit that acknowledges that Jesus Christ has come in the flesh is from God, but every spirit that does not acknowledge Jesus is not from God. This is the spirit of the antichrist, which you have heard is coming and even now is already in the world.” (1 John 4:2-3)

An example of one such false philosophy is the belief that man can earn God’s favor by a certain act or acts. In almost every false religion, meriting God’s favor or earning eternal life is a predominant theme. Earning salvation by works, however, is contrary to biblical revelation. Man cannot work to earn God’s favor; eternal life is a free gift of grace (see Eph. 2:8-9). And that free gift is available through Jesus Christ and Him alone (John 3:1614:6).

We shouldn’t believe everything we hear just because someone says it is a message inspired by God. There are many ways to test teachers to see if their message is truly from the Lord. One is to check to see if their words match what God says in the Bible. Other tests include their commitment to the body of believers (1 John 2:19); their lifestyles (3:23-24), and the fruit of their ministries (4:6). But the most important test of all, says John, is what they believe about Christ. Do they teach that Jesus is fully God and fully man, and that He is the only way to the Father?

Even as believers, we must rely on the discernment given us by the Holy Spirit so that we are not deceived. “Dear friends, do not believe every spirit, but test the spirits to see whether they are from God, because many false prophets have gone out into the world.” (1 John 4:1)  Don’t be gullible, don’t believe just anyone who comes along saying something that sounds good or is even partially true. Because behind the false prophet or false teacher is an evil spirit. Give teachers these tests to see if they are indeed speaking God’s truth.