Why would Shakespeare have Macbeth say that he has avoided Macduff because "My soul is too much charged/ With blood of thine already"?
Macbeth has already ordered the deaths of Macduff's wife and children. Thus, when he says, "My soul is too much charged with blood of thine already," he is saying "I've already killed too many of your family and I don't want to have to kill you also. At this point in the play, Macbeth has grown tired of the constant bloodshed he has caused and has begun to feel guilty about his actions. Thus, he avoids Macduff to avoid spilling more blood. Ironically, this merciful action on Macbeth's part will have disasterous consequences for him later.