We can't earn or work for salvation, it's a gift. But we can earn special praise and special commendation from the Lord, and we can work for rewards! God is no respecter of persons when it comes to Salvation. (Acts 10:34) But when it comes to works and accomplishing something for Him in His Kingdom here on Earth, He is a great respecter of persons!
Heaven is not going to be a classless society. In Heaven, there will be all kinds of grades and levels of reward, just like there will be all kinds of grades and levels of punishment for the unsaved. There will be a different glory with which each person will shine, depending on how much they did for the Lord. Some of the Christian heroes of the Faith, who have been real saints, giving their lives in love that others might be saved, where do they deserve to be?--At the Top, near the Lord in His Court! But some Christians who served poorly and lived selfishly for themselves all their lives will be rewarded poorly!
"Be ye therefore steadfast, unmovable, always abounding in the work of the Lord, for ye know that your labours are not in vain in the Lord!" (1Cor.15:58) You'll be rewarded before long!--Amen?