"You can't serve God & money" was said to the poor.

"“No one can serve two masters. Either you will hate the one and love the other, or you will be devoted to the one and despise the other. You cannot serve both God and money."
(Always see what the therefore is there for).
THEREFORE I tell you, do not worry about your life, what you will eat or drink; or about your body, what you will wear. Is not life more than food, and the body more than clothes? Look at the birds of the air; they do not sow or reap or store away in barns, and yet your heavenly Father feeds them. Are you not much more valuable than they? Can any one of you by worrying add a single hour to your life?
...
So do not worry, saying, ‘What shall we eat?’ or ‘What shall we drink?’ or ‘What shall we wear?’ For the pagans run after all these things, and your heavenly Father knows that you need them.  But seek first his kingdom and his righteousness, and all these things will be given to you as well.  Therefore do not worry about tomorrow, for tomorrow will worry about itself. Each day has enough trouble of its own."

Interesting that when Jesus said you cannot serve two masters he was talking to poor people about not worrying about money because God would provide for them. He wasn't talking only to rich people seeking more & more as we are always taught.

 “No one can serve two masters. Either you will hate the one and love the other, or you will be devoted to the one and despise the other. You cannot serve both God and money."
If you're poor & serve money & God you'll hate money & love God, & you'll be devoted to God but hate money (because you always have to think about it & try to get more because you legitimately are always on the edge of not not having enough). Worry. You have it as a master because you depend on it. You can still serve money while not loving it!