Johnny said: “Can a punna kamma be rooted in ignorance even if it is done out of faith?”.
We need to clarify faith (saddha) first. In Buddha Dhamma, saddha comes through understanding, and different people may have different levels of understanding. Nevertheless, any act done with saddha makes one’s heart joyful, and thus is a punna kamma. This is explained in the post “Kusala and Akusala Kamma, Punna and Pāpa Kamma“.
As also explained in that post, some punna kamma may not be kusala kamma, but they ALWAYS make conditions that can lead to kusala kamma. Buddha taught that punna kamma are NECESSARY to cultivate the Path.
Johnny said: “..we know there is no sculpture of Buddha during Buddha’s time and that the Buddha does not advocate idol worshipping.”
This is absolutely wrong. It is true that Buddha Statues were not there at the time of the Buddha. But worshipping symbols REPRESENTING the Buddha were there at the time of the Buddha. There is the following account in the Tipitaka:
People brought many things to offer to the Buddha at Jetavanarama. If the Buddha was not there, they went back disappointed. When Ven. Ananda mentioned this to the Buddha, the Buddha asked a Bo tree to be planted there and to instruct people to make those offerings to that Bo tree. It was called “Ananda Bodhi“. It was just a symbol representing the Buddha. One’s feelings are based on one’s reverence for the Buddha, not for the symbol.
Of course, the same goes for offering fruits, lights, incense and other offerings to the Buddha statue. Faith is in one’s mind, not in any symbol.
A crude analogy can be given in terms of paper money that we use today. A hundred- dollar bill has no real intrinsic value. But it is accepted by the society to have a value of $100.