In act 2, scene 3, Lady Macbeth, speaking to herself, proclaims:
Naught's had, all's spent,
Where our desire is got without content.
Lady Macbeth has just watched her husband, in front of all the guests at the banquet, seemingly lose his mind. He saw the bloodied ghost of Banquo, but nobody else at the banquet did. Lady Macbeth here realizes that her husband is being driven mad by the guilt he feels for murdering his friend, Banquo. Indeed, the ghost of Banquo can be seen as a manifestation of Macbeth's guilt. This guilt, like the ghost, haunts him. Lady Macbeth's husband has no peace of mind, and no contentment, even though he and his wife, by becoming king and queen, have achieved what they desired and set out to achieve.
The quotation "our desire is got without content" is really a reiteration of the preceding line, "Naught's had, all's spent." When Lady Macbeth says that "all's spent," she means that she and her husband have given up, or "spent" everything to become king and queen. They have forsaken God by killing the divinely sanctified king. They have given up their peace of mind, and they have given up their friends. They have "spent" all of this and all for "naught." This choice of word, "Naught," meaning 'nothing,' suggests that Lady Macbeth considers the titles of king and queen to be meaningless without the peace of mind that should come with those titles. It is because they no longer have this peace of mind that they can not be "content."
Lady Macbeth's lack of contentment is highlighted later in the play, in act 5, scene 1, where she is seen sleepwalking and frantically trying to remove an imagined spot of blood from her hands. This spot of blood symbolizes her inability to find peace of mind. It symbolizes the guilt that has taken that peace of mind, or contentment, from her, just as Banquo's ghost symbolizes the guilt which has taken Macbeth's peace of mind from him.