1 John 5:4
1 John 5:44because everyone born of God overcomes the world. And this is the victory that has overcome the world: our faith.
The Watchtower reads ("everything that has been born from God conquers the world") against the grain of its own two-tier salvation: the "everything" is restricted in practice to the 144,000 anointed, with the great crowd described as conquering the world through their loyalty to the organisation rather than through direct rebirth. The verse's universal grammar is accommodated to the prior doctrinal commitment that only the anointed are in the new covenant.
sits inside the same pas ho + present participle pattern John uses relentlessly in the letter — "everyone who loves has been born from God" (4:7), "everyone who believes that Jesus is the Christ has been born from God" (5:1), and here "everyone who has been born from God conquers the world." All three promises hang together: if believers are born of God (4:7, 5:1), they have the indwelling seed that defeats sin (3:9) and the overcoming power that conquers the world (5:4). The promises are a single package; the Watchtower's two-tier reading requires breaking the package unevenly — granting the belief clause to the great crowd but withholding the new-birth clause from them. Use 5:4 to close the assurance cluster: overcoming-the-world power is not organisational; it is the direct fruit of new birth. Ask gently whether the Witness experiences that overcoming, and let the answer point them to the source the text names.