What does it look like when a true Christian is under the spirit of mammon

Many Christians think that a true Christian can never be under the spirit of mammon, that is, influenced by him. What does it look like when a true Christian is under the spirit of mammon? 

The real give-away sign is that he or she is anxious about daily necessities, whether he can live within his means and pay all his bills. The other sign is that he believes in his "rights", a product of the flesh. 

The reason that any person can be under the spirit of mammon in the first place in his flesh which is hostile against God (Romans 8:7).

When one is feeling anxious, remember what Jesus said in Matthew 6:24-34:

No man can serve two masters: for either he will hate the one, and love the other; or else he will hold to the one, and despise the other. Ye cannot serve God and mammon.  Therefore I say unto you, Take no thought for your life, what ye shall eat, or what ye shall drink; nor yet for your body, what ye shall put on. Is not the life more than meat, and the body than raiment? 

Behold the fowls of the air: for they sow not, neither do they reap, nor gather into barns; yet your heavenly Father feedeth them. Are ye not much better than they? Which of you by taking thought can add one cubit unto his stature? And why take ye thought for raiment? Consider the lilies of the field, how they grow; they toil not, neither do they spin: And yet I say unto you, That even Solomon in all his glory was not arrayed like one of these. Wherefore, if God so clothe the grass of the field, which to day is, and to morrow is cast into the oven, shall he not much more clothe you, O ye of little faith?

Therefore take no thought, saying, What shall we eat? or, What shall we drink? or, Wherewithal shall we be clothed? (For after all these things do the Gentiles seek:) for your heavenly Father knoweth that ye have need of all these things. But seek ye first the kingdom of God, and his righteousness; and all these things shall be added unto you. Take therefore no thought for the morrow: for the morrow shall take thought for the things of itself. Sufficient unto the day is the evil thereof.

That Jesus said, therefore I say unto you,  in the verse 25 immediately after Matthew 6:24 indicates that he is explaining what one should do to not be under the spirit of mammon. Anxiety to fulfill all earthly needs, including the real legitimate ones, such as food and shelter, comes from trying to serve mammon, or being influenced by him:

No man can serve two masters: for either he will hate the one, and love the other; or else he will hold to the one, and despise the other. Ye cannot serve God and mammon.  Therefore I say unto you, Take no thought for your life, what ye shall eat, or what ye shall drink; nor yet for your body, what ye shall put on. Is not the life more than meat, and the body than raiment? 

The anxiety to survive and to ensure one's legitimate earthly needs are met is precisely what it means to be under the spirit of mammon. It does not matter that you give away much money or serve as an evangelist. As long as you have this anxiety, you are under the spirit of mammon.