The opening verses of 1 John 5 are admittedly a bit circular.
"Everyone who believes that Jesus is the Christ has been born of God, and everyone who loves the Father loves whoever has been born of him. By this we know that we love the children of God, when we love God and obey his commandments."
So we know we love the Father if we love the children of God and we know we love the children if we love the Father? We might think that last phrase about obeying his commandments would offer some objectivity as an exit off this merry-go-round. However, it really only serves to further the circularity since the commandment in the Johanine literature is to love one another. Logically speaking, it seems John might as well have said "we know we love the children of God when we love the children of God."
I suppose the disadvantage of a circle, especially in matters of logic, is that it doesn't take us anywhere. We keep going around the same path. It doesn't reveal anything new to us. We start with "love the children of God" and we end with "love the children of God".
But I suppose that is also what makes it an appropriate shape for the Christian life. Our goal isn't to get somewhere new. We don't start with "love the children of God" only as a stepping stone to move onto something more profound. When we are talking about God's love for us, our love for God, and love for God's children, why wouldn't we want this path to loop back on itself as many times as possible? Indeed, any search for something new, some knowledge more profound than loving our brothers and sisters is only a distraction from the path that leads us back to God's love. Truth is not acquired by escaping this circularity. The circularity that is God's love enabling us to love our neighbor leading us back to God's love enabling us to love our neighbor is the most profound truth of all.
As a culture, we are pretty much obsessed with anything new. It might not be an exaggeration to say we are not merely obsessed with new things but with newness itself; anything that will relieve the tedium of our lives and infuse them with new meaning. Our watchword is progress; movement forward. Anything else is failure. Most of the Church seems to adopt a similar model. We are constantly searching for that new thing that will make all the difference in our spiritual lives, our families, our churches. What we try next must always be bigger and better than what we tried before or we might as well admit defeat.
All the while that ancient circle of love of God and neighbor quietly awaits us.
Obviously, there is something to be said for "straining toward what is ahead" and "pressing toward the goal". But John reminds us that pressing forward in the Christian life is not a matter of blazing our own trail. It is entering the circularity of God's love.