In addition, we are also called to be unbelievers. There is a time when unbelief is the right thing. In order to live it is necessary both to inhale and to exhale. These are contradictory things: You cannot inhale and exhale at the same time, but both are absolutely necessary to maintain life. You cannot inhale unless you exhale, and you cannot exhale unless you have inhaled.
It is the same with this matter of belief and unbelief. You cannot believe truth without rejecting error. You cannot accept Christ without rejecting self. This is what John is declaring here in 1 John 4:1-3.
Now, this section comes as a parenthesis in John's discourse on love. And, it is significant that this warning comes in the midst of John's discourse about love, because the false spirits make a great deal out of love. Every cult does what it does and teaches what it teaches in the name of love. The oldest trick in Satan's bag of tricks is to show a spirit of friendly concern and to appear to offer the fulfillment of love.
In the Garden he said, "if you take of this fruit you will become as gods. You will discover the thing you were made for, and which God is trying to keep you from. As your friend, I suggest you take of the fruit and eat". But the Scriptures warn us that the mark of childish immaturity is to be caught up and taken in by that kind of approach, "to be tossed about by every wind of doctrine" {Eph 4:14}, every new teaching that comes along.
The mark of spiritual maturity is unbelief in that which is false and believing in that which is true. Tomorrow, we will consider this proposition in a more deeper fashion.