The Magi are the first-fruits of the Gentiles

"THE Magi are the "first-fruits of the Gentiles" that believed in Christ; because their faith was a presage of the faith and devotion of the nations who were to come to Christ from afar. And therefore, as the devotion and faith of the nations is without any error through the inspiration of the Holy Ghost, so also we must believe that the Magi, inspired by the Holy Ghost, did wisely in paying homage to Christ."

~St. Thomas Aquinas: S.T. III, Q. 36, A. 8. (The manifestation of the newly born Christ)

Adoration of the Magi, by Altichiero da Zevio. 

Fresco, 1378-84; Oratorio di San Giorgio, Padua.