For no fruit is good that does not grow from the root of love. If, however, that faith be present which worketh by love, then one begins to delight in the law of God after the inward man, and this delight is the work of the spirit, not of the letter; even though there is another law in our members still warring against the law of the mind, until the old state is changed, and passes into that newness which increases from day to day in the inward man, whilst the grace of God is liberating us from the body of this death through Jesus Christ our Lord.
Augustine of Hippo, 354 - 430 AD, On the Spirit and the Letter, Chapter 26 (translated by Peter Holmes, Rev. Robert Ernest Wallis, and Benjamin B. Warfield, Nicene and Post-Nicene Fathers, Philip Schaff, T & T Clark and Wm. B. Eerdmans Publishing, 1997, First Series, Vol. V, p. 94).
Is a good work only a good work if motivated by love? What are the implications of this?