Narada was born from the best deliberation of Brahma because Narada was able to deliver the Supreme Lord to anyone he liked. The Supreme Personality of Godhead cannot be realized by any amount of Vedic knowledge or by any number of penances. But a pure devotee of the Lord like Narada can deliver the Supreme Lord by his good will. The very name Narada suggests that he can deliver the Supreme Lord. Nara means the Supreme Lord, and da means one who can deliver. That he can deliver the Supreme Lord does not mean that the Lord is like a commodity that can be delivered to any person. But Narada can deliver to anyone the transcendental loving service of the Lord as a servitor, friend, parent or lover, as one may desire out of ones own transcendental love for the Lord. In other words, it is Narada only who can deliver the path of bhakti-yoga, the highest mystic means for attainment of the Supreme Lord.