(1Co 15:58) Therefore, my beloved brethren, be ye stedfast, unmoveable, always abounding in the work of the Lord, forasmuch as ye know that your labour is not in vain in the Lord.
Paul says that because of the resurrection, nothing we do is in vain. Sometimes we hesitate to do good, because we don't see results immediately. If only we could see from a heavenly perspective, we would understand that we will rarely see the results of our own efforts.
If we truly believe that Christ has finally conquered, then we must adjust our lifestyle to our believes. Don't become so discouraged that you stop working when you don't see results. Do good when the opportunity arise, and remember that your work will have eternal value.