Come unto me, all ye that labour and are heavy laden, and I will give you rest. Take my yoke upon you, and learn of me; for I am meek and lowly in heart: and ye shall find rest unto your souls. For my yoke is easy, and my burden is light.
You're probably like me; work, work, work, go, go, go; even my vacations are like this; I usually need a vacation after my vacation. May be I've been taking the wrong kind of vacation.
Christ speaking in verse 28, "I will give you rest". Rest from what? Working for salvation. While the rest of the world is working to be a good person, working to obtain God's favor and in their self-righteousness working to get to heaven we simply rest in the finished work of Christ and His sacrifice on the Cross. Christ is our Salvation, He is our good and sinless person, He is how we obtain favor with God, and He is our righteousness.
There is nothing left to do, Christ has done all the work for us, He has finished the work of His salvation on His cross. We simply rest in His work of salvation.