Law on the veritical is about God's right over us, to expect and require us to fulfill our humanity. Grace on the vertical is about how God sacrificed His Son to deal with the problem of the Law for us, to have us and make peace with us, as a gift that we cannot and could never earn.
Law on the horizontal is about my rights; it is about what is "right." Grace on the horizontal is about thinking of the good of another and sacrificing your rights to give it to them. Law expects, exacts, requires, and even demands. Grace gives, sacrifices, forgives, and covers.
But what is interesting is that both need each other. It is not that they "balance" each other. One gives meaning and fulfillment and life to the other. The solution is not to find a "happy medium" between the two. Let me explain.
Law without a backdrop of grace may be technically in the "right," but it is cruel and harsh and unrelenting.
Grace without a backdrop of law may be "nice," but it amounts to little more than spinless people-pleasing.
Here is an example. Let's say your teenager had a friend over and they stayed up all night long. It is a Saturday morning now, and they are both dead to the world. It is 9:30am, and you need to clean up the kitchen and do other chores around the house. You normally listen to loud music while doing that -really loud, fast music.
Law would say, "It is your house. It is not your fault that they stayed up all night. Turn on the music and have at it. If it wakes them up, that is not your problem." But Grace says, "I will clean the kitchen with no music or at least with low music. I can handle that in order for them to sleep. They had a good time, and I will let them recover."
But what happens if Grace forgets the backdrop of Law? You believe you have no rights. It is no longer a gift to allow them to sleep in -it is their right. The gift becomes cheap, easy, even expected. It becomes what is due. Reality is lost, and the rights and expectations are flipped on their head.
Isn't that ironic? When Grace forgets the backdrop of Law, it finds a way to wiggle back in there somewhere. But this time it comes in not to give fullness and meaning to Grace but to turn against it and distort it into a form of weak-willed compliance. Grace becomes confused, warped. We do this to God when we imagine that it is "His job" to simply forgive us, so that we can go on living in license however we wish. It isn't His job. His "job" is to be just and holy. His nature objectively hates sin and burns against it. It is grace that He forgives, not something that is owed or due to us. It is a gift. When we forget that what is really owed to us is wrath and exile from God, forgiveness becomes cheap and... expected. The Lawgiver becomes the one on trial, under our law that expects Him to behave as we wish. There is a kind of sick role reversal.
Some of us are habitually and compulsively giving. Others of us are overly assertive and used to asserting our "rights", even at the expense of others. Is the best answer a middle-ground or something completely other, a third option?
I think Jesus answers that for us. If you read Philippians 2, the apostle Paul exhorts us toward humility, toward putting the interests of others before ours. The example he uses of course is Jesus. Jesus owed us nothing. Jesus owed the Father nothing, either -their relationship did not work like that. Jesus voluntarily put aside His divinity, taking on the form of a bondservant. It was grace, pure grace. Yet the backdrop of that grace, the thing that makes that grace so amazing, is the reality of who Jesus is and who we are. Jesus is the divine Son, worthy of all the rights in the universe and beyond. We are sinners, rebels, rejectors of God in how we live, in what we think, and in what we love. Yet He chose to put that aside and give us Himself. He chose to put Himself in subservience to the Father, to become a servant, for our sakes.
Humility is not thinking that you have no rights, that your time is not your own, that your gifts and talents are an open room for anyone to enter and take and steal from, while you are left depleted and exhausted. It is recognizing your rights yet putting them aside to give something to another. It is Grace, grace on top of Law. It is not the absence of rights. It is not allowing others to take advantage of us like a city with no walls. It is not imposed or required. It is voluntarily and selectively putting those rights aside for another.
I believe only the Gospel can really produce this in us -as we see this done for us by Someone much, much greater than ourselves.