1 John 1:8
If we say that we have no sin, we deceive ourselves, and the truth is not in us.
The saved do not live in sin. The saved can sin. You are looking at sin from the wrong point of view. You are probably thinking of only sins that are unto death, the sins that if you live in them you will not inherit the kingdom (Galatians 5:19-21).
But sin is much wider than that, if you know to do good and don't do it, that is also a sin. You can sin on thought level as well I would assume. So everyone will sin. But there is a clear distinction between a saint and a sinner.