Neoplatonism is not a description of the universe offered for its own sake. It is a map for getting back, and the return is the point of the system.
The path begins with ethics. Porphyry set out a scale of virtues that later became standard: civic virtues that moderate the passions, purificatory virtues that detach the soul from the body, contemplative virtues belonging to intellect, and paradigmatic virtues belonging to the level of the Forms themselves. Ordinary decent conduct is the lowest rung, genuinely required but not the goal. Above it the aim is progressive detachment, then contemplation, and finally a union with the One that Plotinus describes as rare, brief and beyond thought. Porphyry reports that his teacher attained it four times in the years they were together, and that he himself had done so once.
The great internal dispute concerns whether contemplation is enough. Iamblichus argued that it is not. On his view the human soul descends completely, retains no part above, and cannot therefore lift itself by its own intellectual effort; what is required is theurgy, divine work, meaning ritual acts using material things (stones, plants, sounds, images, names), that carry a correspondence to the divine levels and through which the gods act upon the soul. The gods do the work; the practitioner supplies the receptacle. Iamblichus insisted this was not magic aimed at compelling the divine but its opposite, and the distinction mattered to him.
Porphyry had been sceptical, and Plotinus is famously reported to have declined to attend rituals on the ground that the gods should come to him. Iamblichus won the argument in practice. Later Neoplatonism, including the school at Athens, was thoroughly theurgic, and Proclus composed hymns, observed cult and wrote on the sacred art of correspondences.
This is why late Neoplatonism looks like a religion as well as a philosophy. It had a doctrine of salvation, a ritual practice, sacred texts including the Chaldean Oracles and the Orphic poems, and a defence of traditional Greek and Egyptian cult as the outward form of a philosophical truth. The emperor Julian's attempt to restore paganism drew directly on this synthesis, and its collapse after his death in 363 removed the movement's only prospect of state support.