St Paul tells us that the fruit of the Spirit is love, joy, peace, longsuffering, gentleness, goodness, faith, Meekness, temperance: against such there is no law (Gal 5:22-23). The Blessed Jerome, commenting on this verse, writes:
What deserves to hold the first place among the fruits of the Spirit if not love? Without love other virtues are not reckoned to be virtues. From love is born all that is good. Now by joy people mean an elation of mind over things that are worthy of exultation, whereas gaiety is an undisciplined elation of mind which knows no moderation... We should not suppose that peace is limited to not quarreling with others. Rather the peace of Christ, that is, our inheritance, is with us when the mind is at peace and undisturbed by conflicting emotions.Cited here.