Matthew 6:24
No man 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.
Luke 16:13
No servant can serve two masters: for either he will hate the one, and love the other, or he will cleave to the one, and despise the other. Ye cannot serve God and Mammon.
2 Thessalonians 2:11-12
And therefore God shall send them strong delusion, so that that they shall believe a lie,
James 1:8
A double-minded man is unstable in all his ways.
James 4:4
Ye adulterers and adultresses, know ye not, that the friendship of the world is enmity against God? Whosoever therefore desireth to be a friend of the world, is an enemy of God.
1 John 2:15
Love not the world, neither the things that are in the world: if any one 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: O that thou wert cold or hot!