A person with divided loyalty cannot be trusted.
Read: James 1:6-8
6 But when you ask him, be sure that your faith is in God alone. Do not waver, for a person with divided loyalty is as unsettled as a wave of the sea that is blown and tossed by the wind. 7 Such people should not expect to receive anything from the Lord. 8 Their loyalty is divided between God and the world, and they are unstable in everything they do.