Hinduism

Narada Bhakti Sutra, Aphorism 20

It is indeed thus.
Four definitions are now given of Love. The first two may be said to be ritualistic devotion. The last two represent the two great schools of dualists and non-dualists. Narada Sutra is dualistic, Sandilya Sutra is non-dualistic.
The first claims a Deity external to the soul and eternally separate.
The second recognises one Eternal Self only as manifesting in all creatures: these apparently separate existences may be produced by limitation of Love in them and the production of selfishness. When the fulness of Love is reached, the recognition of “One without a second” is attained. As long as there is no desire for Love, which dissolves all limitations, there is individual selfish life following life, with the attendant miseries of birth, growth, old age, decay and death. There is no peace, no goal for those who do not learn to love: they beat backward and forward on the storm-tossed ocean of separation called the world, striving ever for the most futile and ephemeral of things, for personal and separate existence, for self-solicitude. Alas! what misery is theirs. Such striving fulfils not even the average conceptions of ethics and philosophy.
Self-affirmation is death; self-negation is life eternal.
Sankaracharya, the great expounder of the non-dualistic system, has pointed out that the teaching of non-duality comes as an amplification of other doctrines, not as a contradiction of them.
He, then, who holds this doctrine, can look with perfect sympathy and patience upon those who still need, or still see, a Deity, or deities, in nature, separate from themselves.
The mind cannot always dwell in the highest abstractions: it can then drop back with safety to the conception of itself as separate from Deity. Upon so doing, in reality, the centre of consciousness being lowered, the mind again takes on the form of “I” and sees what is beyond this conception, the Changeless Self, God, as now apparently outside and beyond itself—as non-I. From this standpoint it strives for complete surrender to the Divine Will, as slave, as servant, or as lover. With complete acquiescence there comes complete identity. In complete love there is no room for “I” and “thou.”

Source Nârada, Bhakti-Sûtras (« Nârada Sûtra : An Inquiry into Love »), trad. E. T. Sturdy, 1896, archive.org · Contents