Isaiah 49:4
This verse is very encouraging to those who are ministering for the Lord in discouraging circumstances.  It assures us that our labor is never in vain.  God always notices the service that we do for Him and He is always faithful to reward it.  It is comforting to know that nothing we do for Him escapes His notice. 
The second comforting thought is that the quality of our service is not measured in results.  This verse demonstrates the fact that we can be doing exactly what God wants us to do and yet not see results.  It is truly comforting to know that the results lie with the Lord and all I have to do is faithfully give out His message. 
What a challenge to refine my life as well!  To know that I am not measured on the basis of the numbers I achieve but on how closely I reflect my Lord ought to drive us to deeper levels of commitment to Him.  Let us strive to remain faithful always to our Lord.