Manoah and his wife appear to be passive characters, which don't even pray to God to resolve their infertility. On the other hand, Shimshon is a described as energetic, passionate, and impulsive. His nazirite is meant to channel these qualities to a positive place. Parashat Naso presents the nazirite as a mitzvah that leads to kedusha, while the haftara emphasizes the problems that stem from becoming a nazir.

Courtesy of the Virtual Beit Midrash, Yeshivat Har Etzion