Here is a spiritual principle: We cannot exercise love unless we are experiencing grace. You cannot truly love others unless you are convinced that God’s love for you is unconditional, based solely on the merit of Christ, not on your performance. Our love, either to God or to others, can only be a response to His love for us.
Jerry Bridges
Transforming Grace, NavPress, 2008, 160
GraceQuotes.com 
The problem with this kind of thinking is that it claims unbelievers are incapable of love.
Not an easy message to sell to them – you don’t love your kids because you’re not a christian.
As an alternative, if this is a christian spiritual principle, there must be scripture for it – so why does the author not support his claim from the bible?
I cut the quote off too soon for you Jeremy! Here is the next part of Jerry’s thought: “John said, ‘We love because he first loved us’ (1 John 4:19).”
I still don’t see how this quote is a good exposition of the passage. Not least because the passage is all about the agape kind of love and our English word covers many other kinds of love.
John’s message is about the priority of loving God and fellow christians [not others in general]. Bridges message would allow someone to say that they can’t love properly yet because they haven’t experienced enough grace yet.
The whole of the second sentence is something Bridges believes about grace that is nowhere to be found in the whole of the passage he quotes.