Not being double minded
|Janus. Republican coin, c.225-212;|
(Kunsthistorisches Museum, Wien) Source
Double minded literally means having one's soul or heart split between God and the world. It means the man trusts God only so much, and when trials come, he falls away. He is unstable. The verse is speaking of the unbeliever.
If Christians are told not to be double-minded as unbelievers are, then it stands to reason we are to be single minded. Single-minded about what? Jesus.
Philippians 4:8 says, "Finally, brothers, whatever is true, whatever is honorable, whatever is just, whatever is pure, whatever is lovely, whatever is commendable, if there is any excellence, if there is anything worthy of praise, think about these things."
And it stands to reason that all those excellent things come from Who? Jesus. He is the only commendable, He is the source for all that is good. He is the only source of whatever is true.
So if anyone ever says to you "You're so heavenly minded you're no earthly good" you know they are a double-minded man, and that you are not. Being single minded about heavenly things IS the good. The only Good there is in all the universe.