Paul returns to the subject of a particular heresy that is threatening the church at that time, but he instructs Timothy not to engage the arguments about it and does not specify the heresy here. We know that they were talking in part about food laws and imposing further restrictions on the Church. These restrictions are not necessarily wrong and may in fact be helpful, but these doctrines are not to be placed on the people. Mark 7 tells us that all foods are morally clean. Nothing is to be rejected if it received with thanksgiving, as this sort of spiritual appetite can never be satisfied.