Matthew 6:24
No man can serve two masters: for he will either hate the one, and love the other; or he will adhere to the one, and disregard the other. Ye cannot serve God and mammon.
Luke 16:13
No domestic can serve two masters: for either he will hate the one, and love the other; or he will cleave to the one, and neglect the other. Ye cannot serve God and mammon.
2 Thessalonians 2:11-12
And for this cause God shall send unto them the energy of delusion, that they should believe a lie:
James 1:8
A double-minded man is unsteady in all his ways.
James 4:4
Ye adulterers and adultresses, know ye not that friendship with the world is enmity against God? whosoever therefore will be a friend of the world is set down an enemy to God.
1 John 2:15
Love not the world, neither the things which are in the world. If any man love the world, the love of the Father is not in him.
Revelation 3:15-16
I know thy works, that thou art neither cold nor hot: