'Mammon' is an ancient word that means 'wealth' or 'riches,' and is used in the Bible in a negative way, denoting worldly wealth as opposed to spiritual wealth. 'Riches' in the Bible represent knowledge and understanding of spiritual things -- good things to have. But such knowledge is not restricted to good people; it's possible to know and understand a great deal about spiritual things and not use it, or to have it and use it toward selfish ends. This is the kind of behavior that 'mammon' describes.
Luke 19:11-19
11
And as they heard these things, he added and spake a parable, because he was nigh to Jerusalem, and because they thought that the kingdom of God should immediately appear.
12
He said therefore, A certain nobleman went into a far country to receive for himself a kingdom, and to return.
13
And he called his ten servants, and delivered them ten pounds, and said unto them, Occupy till I come.
14
But his citizens hated him, and sent a message after him, saying, We will not have this man to reign over us.
15
And it came to pass, that when he was returned, having received the kingdom, then he commanded these servants to be called unto him, to whom he had given the money, that he might know how much every man had gained by trading.
16
Then came the first, saying, Lord, thy pound hath gained ten pounds.
17
And he said unto him, Well, thou good servant: because thou hast been faithful in a very little, have thou authority over ten cities.
18
And the second came, saying, Lord, thy pound hath gained five pounds.
19
And he said likewise to him, Be thou also over five cities.
