Nice to meet you Kathryn!
The way I read it is that trust in Him is what He declares righteous. The reverse of that would be that not trusting Him is unrighteousness. So when I am not trusting (abiding) in Him, but am working to "be good" instead of seeing that i CAN'T be good because there is no good IN me, I have become and am walking unrighteously.
To trust Him is harder than it first appeared to me. If I worry about my job, I am not trusting\abiding. If I worry about my retirement account taking a hit, I prove my unrighteousness because it is trust in Him and what He has said He will do that He says is counted to us as righteousness.
Righteousness is by trust\faith. But I can't say I don't sin if I plainly see I do when I become angry at someone for not showing care or respect to me.
The op asked if we are sinners after we meet God.
This is very hard to struggle with. I need more coffee and a piece of fudge.