Those who are not careful in eating and drinking, many evils arise from them. This path becomes very difficult due to the lack of distinction between halal and haram. Such people do not have control over their desires, because haram food produces haram deeds. Eating halal and pure food produces good deeds, and such people gain control over their desires very quickly. Those who are concerned about reforming themselves should take great care to eat halal food.
There is a special connection between eating halal and righteous deeds, which I understood from this verse:
يَا أَيُّهَا الرُّسُلُ كُلُوا مِنَ الطَّيِّبَاتِ وَاعْمَلُوا صَالِحًا
Allah Almighty is addressing His prophets, saying, "O Our Messengers! Eat pure and good things and do good deeds."
In this verse, the teaching of eating halal is given in a wonderful way. Prophets are infallible; there is no possibility of eating haram here, but despite this, commanding the prophets to eat halal emphasizes the importance of eating pure things, and after eating pure things, commanding to do righteous deeds makes it clear that when you eat pure, good and pure deeds will also be produced, and the self will become obedient to obedience very easily and conveniently. Because pure food will produce luminous and pure blood, and that blood will spread to the eyes, ears, tongue, and all organs, creating the ability and desire for good deeds, and good intentions will be generated in the heart, and the organs will be obedient to the intention of good.