Both Lord Buddha and Acarya Sankara paved the path of theism, and Vaisnava acaryas, specifically Lord Sri Caitanya Mahaprabhu, led the people on the path towards a realization of going back to Godhead

Expressions researched:
"both Lord Buddha and Acarya Sankara paved the path of theism, and Vaisnava acaryas, specifically Lord Sri Caitanya Mahaprabhu, led the people on the path towards a realization of going back to Godhead"

SB Canto 1

Lord Buddha preached the preliminary principles of the Vedas in a manner suitable for the time being (and so also did Śaṅkarācārya) to establish the authority of the Vedas. Therefore both Lord Buddha and Ācārya Śaṅkara paved the path of theism, and Vaiṣṇava ācāryas, specifically Lord Śrī Caitanya Mahāprabhu, led the people on the path towards a realization of going back to Godhead.

SB 1.3.24, Purport:

Technically Lord Buddha's philosophy is called atheistic because there is no acceptance of the Supreme Lord and because that system of philosophy denied the authority of the Vedas. But that is an act of camouflage by the Lord. Lord Buddha is the incarnation of Godhead. As such, he is the original propounder of Vedic knowledge. He therefore cannot reject Vedic philosophy. But he rejected it outwardly because the sura-dviṣa, or the demons who are always envious of the devotees of Godhead, try to support cow-killing or animal-killing from the pages of the Vedas, and this is now being done by the modernized sannyāsīs. Lord Buddha had to reject the authority of the Vedas altogether. This is simply technical, and had it not been so he would not have been so accepted as the incarnation of Godhead. Nor would he have been worshiped in the transcendental songs of the poet Jayadeva, who is a Vaiṣṇava ācārya. Lord Buddha preached the preliminary principles of the Vedas in a manner suitable for the time being (and so also did Śaṅkarācārya) to establish the authority of the Vedas. Therefore both Lord Buddha and Ācārya Śaṅkara paved the path of theism, and Vaiṣṇava ācāryas, specifically Lord Śrī Caitanya Mahāprabhu, led the people on the path towards a realization of going back to Godhead.