What Rage activates

Rage turns on the defender package. The first creature you hit can be hindered by Ancestral Protectors, Spirit Shield becomes available as a reaction to protect someone else, and Vengeful Ancestors later adds force damage when that shield prevents damage.

What remains useful outside Rage

Consult the Spirits is an exploration and information feature and does not depend on Rage. Outside Rage, the character is otherwise a normal Barbarian with the usual martial, movement, and defensive tools.

The normal Rage restrictions still matter

Ancestral Protectors and Spirit Shield reward committing to Rage, but Rage still follows the normal 2014 restrictions on spellcasting and concentration. A multiclass caster therefore has to choose between maintaining magic and activating the Path's strongest protective tools.

Why Rage duration matters

When Rage ends, Ancestral Protectors and Spirit Shield stop functioning until the next Rage. At high level, maintaining Rage is therefore important not only for your own durability but also for the allies relying on your protection.