Passage
hereby we know that we abide in him and he in us, because he hath given us of his Spirit.
hereby we know that we abide in him and he in us, because he hath given us of his Spirit.
1 John 4:11 Beloved, if God so loved us, we also ought to love one another.
1 John 4:12 No man hath beheld God at any time: if we love one another, God abideth in us, and his love is perfected in us:
1 John 4:13 hereby we know that we abide in him and he in us, because he hath given us of his Spirit.
1 John 4:14 And we have beheld and bear witness that the Father hath sent the Son [to be] the Saviour of the world.
1 John 4:15 Whosoever shall confess that Jesus is the Son of God, God abideth in him, and he in God.
The verse centers on "Spirit", "hereby", "abide", "hath", and "given". It is saying that the verse draws attention to "Spirit" and "hereby", so its meaning should be read from those terms before moving to application.
The nearby context moves from verse 12's "No man hath beheld God at any..." into verse 14's "And we have beheld and bear witness...", so "Spirit" and "hereby" belong inside that flow. In 1 John context, the local focus is Christ, faith, and discipleship.
A plain takeaway is to answer the verse's own emphasis on "Spirit" and "hereby" with trust shaped by these words, not by a vague optimism outside the passage.