Atheists typically argue that all things can be explained by nature. Anything apparently supernatural only awaits a more developed science to explain it. God is never needed. An atheist friend of mine holds this position firmly, except for one mystery in his life: his love for his wife. He can list the qualities he admires about the woman he married. He can tell you why he finds her attractive, interesting, and funny. Yet he admits, he might find those qualities in some other woman, perhaps even to a greater degree. Still he would not love that woman the way he loves his wife. With her, there is something extra, something particular, something he can’t explain and can’t find anywhere else. Exploring the mystery of his own love is the closest he’s ever come to the mystery of grace. If he ever does find God, it will probably be because he first found his wife.
Love didn’t mystify Jesus. He understood it perfectly. He also understood why, from all eternity, the Father loves him: “This is why the Father loves me, because I lay down my life in order to take it up again.” The Father loves his Son because the Son (like the Father) pours himself out in love. Because the Son loves, he is loved. This has bound them from eternity. Translated into human terms, divine love was shown to us on the Cross, so that, seeing love, we too might love the Son as the Father does. Loving the Son, the Trinity comes to dwell within us: “Whoever loves me will keep my word, and my Father will love him, and we will come to him and make our dwelling with him” (Jn 14:23). It is by the way of love that “we are God’s children now.”
As my atheist friend will hopefully someday discover, love is a grace. It has its origin in God. It cannot finally be explained without God. The author of love, God is also its measure. Within every love (between friends, children and parents, or spouses) there is a seed of grace that aspires to grow to God-like proportions. It needs faith and hope to water it. That is, it needs fidelity and perseverance, especially through suffering and trial, to ensure that this particular love reaches its potential. One’s love is entering maturity when it is willing to sacrifice. It enters maturity when it begins to look like Jesus’ love. Love finds itself through the Cross. When we love Jesus on the Cross, God comes to dwell with us. But when we ourselves, for love of our friends, go to the Cross, it is we who go to dwell with God.