The main thrust of John's letter is to declare the love of God, and to make clear how that love differs from the lusts of the world. His recipients are warned that their actions must match their declarations, if they are to be believed truly sons of God. They are warned that much falsehood comes in the name of Christ, and given the tools of determining the truth from the lie. The core of the message is that we must abide in God's love, by the power of the Holy Spirit, given through the work of the Son, evidenced by our willing obedience to His commands - especially that we evidence His love in our treatment of others.