When you're admonished to take courage, you know it is a warning signal against what is or may come. Only the wise understand this language and put it into proper perspective. When we work, we naturally expect a paycheck. The Bible says every worker deserves his wages (1 Timothy 5:18). However, we often see this principle violated and rewards withheld unfairly. The drive to do more is motivated by the proportionate return on work done. But what happens when this expectation is truncated? We run into frustration and possibly depression. 
While we continue to work and expect a reward, the verse clearly teaches us how we should conduct ourselves. If you try your best with all your righteousness and sincerity but still don't see results, the prescription is "Don't let your hands be weary". This very much blends with Paul's admonition in Galatians 6:9 to continue doing good and waiting expectantly for the day of your reward. 
If you want your story archived among the shelves of the greats, then you must be courageous enough to tackle delay, lack, deprivation, segregation, victimization, and every ill that threatens your reward in the end. Don't give up!

Dear Heavenly Father, thank You for Your words of encouragement. Strengthen my hands to continue doing what is expected of me. Every seed I have sown shall reap a fruitful harvest for me. Every work I have put my hands to do shall prosper. No matter the setbacks I face now, I have my hope in Christ, that in the end, I will be rewarded. Help me stay committed to the work of the ministry, the career I'm building, and every kind of good work I've committed myself to. 
In Jesus's name I pray. Amen.