Deontological ethics is concerned with actions, not consequences. To act with good intention but have a bad outcome is still moral. Similarly if the intention is bad, then it is wrong in all circumstances and situations, even if it turns out for the best. If benefiting from the act is the motivation for the action, it negates any morality from a good deed. To be good and act morally is to do ones duty - duty being to obey moral law.
"Two things fill the mind with ever new and increasing admiration and awe...the starry heavens above me and the moral law within me"
Kant (1788).
Kant believed that humans know the moral law through reason and without reference it the consequences, and that it was part of people 's duty not to be distracted by their emotions. If moral law dictates you ought to do something, it implies that it can be done, as it is not our duty to do the impossible. Therefore there is no excuse not to obey natural moral law.
Kant maintained humans ' work towards an ultimate end in which human virtue and happiness is brought together, and justice prevails. This is what is known as the summum bonum. As it is impossible to achieve it in this life, he said it was reasonable to assume that there would be a next life with God, where there is an opportunity for reaching the supreme good. In his opinion, morality leads to God.
He also believed that morality is prescriptive.