List examples that show that Macbeth is aware of the difference between good and evil and knows when his actions are evil.

There is a change in the behaviour of Macbeth from the
early Acts (I, II), and the turning point for Macbeth is the manifestation of the ghost
of Banquo, a figment (possibly) of his guilty conscience.  This will be the last time
that Macbeth suffers a pang of guilt or any awareness that his actions are evil.  From
his first appearance in Act IV to the end of the play, his only concern in the play is
to hold onto the kingship, whatever and whomever might get in his way.  So, it is in the
early Acts of the play that we must look for this awareness of good and evil in his
thoughts and actions.

In these opening Acts, the biggest
sign of his awareness that the temptation to kill Duncan and fulfill the witches
prophecy so that he can become king is an evil one comes in his soliloquies.  These
conversations with the audience, that take place when he is alone onstage, come in Act
I, scene vii; Act II, scene i; and Act III, scene i.  All of these speeches reveal
Macbeth's concern that what he does will, as he admits in Act I, scene
vii:

commend
the ingredients of [his] poison'd chalice

To [his] own
lips.

This line reveals an
awareness that the evil concoctions he creates for others will also be the agent of his
own demise.  And, in each speech, he must fight with himself a bit to overcome his
better nature.

In Act II, scene i, he confesses to having a
"heat-oppressed brain," or mental anguish, about the dagger that he must take up to
commit the murder.  The appearance of the apparition of a dagger only reminds him to get
himself back on track and do what must be done, even if it is wrong --
murder.

And in Act III, scene i, he plots to murder Banquo
and his son Fleance so that the prophesy that Banquo's issue will be kings won't be
fulfilled, but also because Macbeth's

readability="13">

. . . fears in
Banquo

Stick deep.  And in his royalty of
nature

Reigns that which would be fear'd. .
.

. . .There is none but
he

Whose being [Macbeth does] fear.  And under
him

[Macbeth's] Genius is
rebuked.

Macbeth admits here
that Banquo is a better man than him, and this is a clear recognition of his own evil. 
Macbeth now lists his own evil nature as a justification for killing Banquo, an act he
must commit so that Banquo's light of goodness will not outshine Macbeth's evil
one.

For more on these speeches and how they reveal
Macbeth's self-awareness, please follow the links below.