Jesus’ is stating this dual dictum as a summary of the “Law (Torah) and the Prophets”. But according to Paul’s authoritative teaching, believers in Christ are no longer under the authority of Torah. We recognize the moral principles to which “the Law and the Prophets” point, but we do not recognize that principles as Law.

Rather Christians live by the Spirit, which creates the “fruits,” which are not governed by any law (http://biblia.com/bible/esv/Ga5.22-23).

Therefore, Jesus’ dictum does not directly govern Christian behavior, except as that behavior is guided by the fruits of the Spirit. It follows that what is decisive is not “love of neighbor,” but the diverse and existentially concrete ways in which the fruits of the Spirit are manifested in the lives of the believer and church. And I certainly don’t think that the unregenerate world has any authority to tell believers what those “fruits” will be.

True, but without neighbor-love is not our love for God false? i.e. is it not the proof of the pudding – if we do not love our neighbor we prove we do not truly love God.