And that was the ONLY thing they needed to do.
It cannot be used as a justification for works based salvation and adding all kinds of extras that people must do in addition to looking.
Faith in God moved the Israelites to obey by going and looking upon a brass serpent. Yet no one today can be saved by going and looking upon a brass serpent. Faith in God in the NT requires one repent Lk 13:3 confess Mt 10:32-22 be baptized Mk 16:16.