Why is it said that without Christ we can do nothing?

'For without me ye can do nothing' (John 15:5) conveys the complete dependence of believers on Christ for all aspects of spiritual life. Just as branches draw nourishment from the vine, Christians draw strength and spiritual vitality from a relationship with Christ. Attempting to live the Christian life apart from Him leads to barrenness and defeat. By acknowledging our dependence on Christ, we align ourselves with His purpose and receive the necessary grace to live a life that reflects His glory and bears lasting fruit.