Believers have nothing to fear, for even Satan’s hosts with their perversions can’t take them out of the Lord’s hand. Here, as in 2:18–27 , protection against error or victory over it are guaranteed by sound doctrine and the indwelling Holy Spirit who illumines the mind.

bible.com/bible/100/1jn.4.4.NASB1995

Notes: Taken from John MacArthur Study Bible