Pantheism is the more general position that God and all of the universe are the same. In this view, God is in fact equated with mankind (and everything else).
I don't fully understand the position, but it seems that Gottfried Leibniz proposed in La Monadologie the idea that everything, including people, are of the same substance as God:
47. Thus God alone is the primary unity or original simple substance, of which all created or derivative Monads are products and have their birth, so to speak, through continual fulgurations of the Divinity from moment to moment, limited by the receptivity of the created being, of whose essence it is to have limits. (Theod. 382-391, 398, 395.)
In both cases, it seems that there are ethical implications that go along with the metaphysical ones. (I notice you want to exclude the metaphysical question so the answer so far might not be helpful.) For Pantheists, duty to God extends to a duty to all of creation and therefore to other people as well. Leibniz makes this consideration his final point:
90. Finally, under this perfect government no good action would be unrewarded and no bad one unpunished, and all should issue in the well-being of the good, that is to say, of those who are not malcontents in this great state, but who trust in Providence, after having done their duty, and who love and imitate, as is meet, the Author of all good, finding pleasure in the contemplation of His perfections, as is the way of genuine 'pure love,' which takes pleasure in the happiness of the beloved. This it is which leads wise and virtuous people to devote their energies to everything which appears in harmony with the presumptive or antecedent will of God, and yet makes them content with what God actually brings to pass by His secret, consequent and positive [decisive] will, recognizing that if we could sufficiently understand the order of the universe, we should find that it exceeds all the desires of the wisest men, and that it is impossible to make it better than it is, not only as a whole and in general but also for ourselves in particular, if we are attached, as we ought to be, to the Author of all, not only as to the architect and efficient cause of our being, but as to our master and to the final cause, which ought to be the whole aim of our will, and which can alone make our happiness. (Theod. 134, 278. Pref. [E. 469; G. vi. 27, 28].)
At least Gottfried Leibniz and any philosopher who holds a pantheistic view are examples of philosophers who equate mankind with God at least in part. (I submit a philosopher who himself claims to be God in full would either be crazy or equivocating on the meaning of