Abandon wrongdoing.
It can be done.
If there were no likelihood, I would not ask you to do it.
But since it is possible
and since it brings blessing and happiness,
I do ask of you:
abandon wrongdoing.

Cultivate doing good.
It can be done.
If it brought deprivation and sorrow, I would not ask you to do it.
But since it brings blessing and happiness,
I do ask of you:
cultivate doing good.
Anguttara Nikaya

Once, the Lord dwelt amongst the Sakyans in the Banyan Tree Monastery at Kapilavatthu, and while there, Mahanama the Sakyan came to him and asked;
"How, Lord, does one become a lay disciple?"
"When one has taken refuge in the Buddha, the Dhamma and the Sangha, then one is a lay disciple".
"How, Lord, is a lay disciple virtuous?"
"When a lay disciple abstains from killing, stealing, sexual misconduct, lying and drinking intoxicants, then he is virtuous."
Anguttara Nikaya, Vol IV

As a bee gathering nectar does not harm or disturb the colour and fragrance of the flower;
so do the wise move through the world.
Dhammapada: Flowers, verse 49

Irrespective of whether we are believers or agnostics, whether we believe in God or Karma, everyone can pursue moral ethics.

We have the ability and the responsibility to choose to direct our actions on a virtuous path.
When we weigh a particular act, to determine whether it is moral or spiritual, our criterion should be the quality of our motivation. When someone deliberately makes a resolution not to steal, if he or she is simply motivated by the fear of getting caught and being punished by the law, it is doubtful whether engaging in that resolution is a moral act, since moral considerations have not dictated his or her choice.
In another instance, the resolution not to steal may be motivated by fear of public opinion: "What would my friends and neighbors think? All would scorn me. I would become an outcast." Though the act of making a resolution may be positive, whether it is a moral act is again doubtful.
Now, the same resolution may be taken with the thought "If I steal, I am acting against the divine law of God." Someone else may think, "Stealing is nonvirtuous; it causes others to suffer." When such considerations motivate one, the resolution is moral or ethical; it is also spiritual. In the practice of Buddha's doctrine, if your underlying consideration in avoiding a nonvirtuous act is that it would thwart your attainment of a state transcending sorrow, such restraint is a moral act.
An Open Heart: Practicing Compassion in Everyday Life

Sometimes people mistakenly look on vows and pledges as if these were a type of punishment, but this is not at all the case. For example, just as we follow certain methods of eating and drinking to improve our health and certainly not to punish ourselves, so the rules the Shakymuni Buddha formulated are for controlling counter-productive ill-deeds and ultimately for overcoming afflictive emotions, because these are self-ruinous. Thus, to relieve oneself from suffering, one controls the motivations and deeds producing suffering for one's own sake. Realizing from his own experience that suffering stems from one's own afflictive emotions as well as actions contaminated with them, he sets forth styles of behavior to reduce the problem for our own profit, certainly not to give us a hard time. Hence, these rules are for the sake of controlling sources of harm.
Yoga Tantra: Paths to Magical Feats

Buddhists take a vow of morality in the context of first taking refuge--in Buddha, in the states of realization, and in the spiritual community. Refuge is the foundation for the practice of morality. Buddha teaches us how to find refuge from suffering and limitation, but the chief refuge, or source of protection, is found in the states of realization achieved through practicing morality, concentrated meditation, and wisdom. ...A lama from the Drukpa Kagyu tradition and I were very close. We met frequently and always used to joke, teasing each other back and forth. On one occasion I asked him about his spiritual experience. He told me that when he was young, he was staying with his lama who had him perform the preliminary practice of making a hundred thousand prostrations to the Buddha, the doctrine, and the spiritual community. Early in the morning and late in the evening he had to make prostrations on a low platform the length of his body. His lama was meditating in the dark in the next room; so to trick him into thinking he was making prostrations he would tap with his knuckles on the prostration platform. Years later, after his lama passed away, he was taking a meditation retreat in a cave, during which he recalled his lama's great kindness over years of training him, and he wept and wept. He almost fainted, but then experienced the clear light, which he continuously practiced. Subsequently, after successful meditations he occasionally would remember past lives in vivid reflections before him.
How to Practice: The Way to a Meaningful Life