This section is from the book "Some Contributions Of South India To Indian Culture", by S. Krishnaswami Aiyangar. Also available from Amazon: Some Contributions of South India to Indian Culture.
How much of this development may be due to any direct Gupta influence we are not in a position to. trace in detail yet. It is impossible that there should not have been that kind of influence, but the whole of the Pallava development in point of religion of the Bhakti school is explainable without this external stimulus. It certainly was the age for the south of a certain amount of reorganisation of the Brahmanical religion such as it was in the earlier time. The reorganisation seems to have taken the form of a great emphasis being laid on what is generally described as "theistic religion" - religion whose centre and heart-core is a personal God watchfully beneficent for the salvation of devotees. Such a movement was called for to remedy one of the vital defects of Vaidic Brahmanism, and the great success that attended the early efforts of Buddhistic teachers, and to a certain degree of the Jain as well, was due to the Congregationalism of both these religious systems. It is the need therefore of a religion that would appeal to the masses that led to this great development in Brahmanism in the period of Brahmanical reorganization as against Buddhism and Jainism. The recognition of a personal God and of popular religion necessitates the form of worship associated with temples.