What do you mean by sincerity? What is the explanation?

It means to correct your mind seriously, that is, to abstain from greed, ignorance, three poisons and all kinds of evil things. Synonymous with "do the right thing with your heart" According to the download of the Infinite Life Sutra, the Buddha said that Maitreya and others can be righteous in this world, do not do all kinds of evil, and achieve supreme virtue, which is unparalleled in the ten worlds because of the natural kindness of the Buddha's land, heaven and people. It is not only the beginning of doing good and stopping evil in a general sense, but also the foundation of meditation in Zen forest. Tuen Mun Police Training Volume 1 (Senior Four or Senior Eight? 1July 947 10): "Keep a clear head, keep an open mind, put your feet away, close your eyes, turn your back on your ears, remain ignorant and sink forever." p5877