Listening to: Bach: Violin Concertos (Hahn)
Love can only be fruit, it cannot take the place of the tree of faith. But there is a constant attempt in the legal scheme to substitute love for faith [...]
[In] Luke's story of the woman in the house of a Pharisee who anointed Jesus' feet from an alabaster jar. The Pharisee, Simon, was found outstripped by the woman not only in faith, but also in his pride - the righteousness of the law (which is love). Jesus said to the woman, "Your faith has saved you; go in peace" (Luke 7:50). Her faith came from the preached word heard earlier: "Your sins are forgiven," and this finally revealed what Jesus meant when he told Simon, "Her sins, which were many, have been forgiven; hence she has shown great love" (Luke 7:47). Love, it turns out, is either understood in relation to the law - in which case it is a work and cannot bear our trust - or it is simply what happens when Christ has forgiven a sinner.
(pp.235-236, Steven Paulson, Lutheran Theology)
So, when we preach the law, we tell people to "love the Lord your God". But when we preach the Gospel we call people to "believe the Lord your God", and out of that belief (which is receiving the seed of the promise of God himself and his forgiveness) love springs spontaneously. Love is greater because love is the eternal goal (1 Cor 13:13), but it cannot be found without faith receiving the Spirit in the promise of Christ who creates it.