I’ve heard many passages read and interpreted in order to help people understand and accept that God is their Father and that they are children of God. Usually, this is called “assurance of salvation.” But, I don’t remember anyone using this verse:
We know that we have passed out of death into life, because we love the brothers. Whoever does not love abides in death. (1 John 3:14 ESV)
Are you demonstrating love to your brothers and sisters in Christ? If so, then you are no longer dead in your sins; you are now alive in Christ. (And, remember how John defines love just a few sentences later – see 1 John 3:17.)
And, if you are inclined to think that the second part of that verse (“Whoever does not love abides in death”) is a little drastic… it is. But, it is also a consistent theme in John’s letter. For example, see 1 John 4:20.
Very power passages… and love is a very powerful assurance.