Those who are active in Christian service must beware of two opposite pitfalls: the elation that comes with success on the one hand, or the discouragement that comes with failures, on the other.
These may be considered by some as trivial, but the history of the Christian ministry will not support this conclusion. They are critically dangerous and should be guarded against with great care.
The disciples returned to Christ with brimming enthusiasm saying "Lord, even the devils are subject unto us through Thy name," and He quickly reminded them of another being who had allowed success to go to his head "
"I beheld Satan as lightning fall from heaven," He said "In this rejoice not, that the spirits are subject unto you but rather rejoice because your names are written in Heaven."
The second of these twin dangers need not be labored. Every minister of the gospel knows how hard it is to stay spiritual when his work appears to be fruitless. Yet he is required to rejoice in God as certainly when he is having a bad year,as when he is seeing great success, and to lean heavily upon Paul's assurance that "your labour is not in vain in the Lord."
...Be ye steadfast, unmoveable, always abounding in the work of the Lord,forasmuch as ye know that your labour is not in vain in the Lord. - 1 Cor. 15:58