Allah will be opponent to Three types of People
[Sahih Bukhari: Volume 3, Book 36, Number 470]
Narrated Abu Huraira (Radi Allah Anhu): The Prophet (sal-allahu-alleihi-wasallam) said, "Allah said, 'I will be an opponent to three types of people on the Day of Resurrection:
1. One who makes a covenant in My Name, but proves treacherous;
2. One who sells a free person and eats his price; and
3. One who employs a laborer and takes full work from him but does not pay him for his lab our.' "