Heavenly Rewards for the Righteous
There is a system of balances found in the Scriptures when it comes to rewards (but not to salvation which is a gift.) Quality works performed for the glory of God to win the souls of men, when tested and found genuine, will earn crowns for the faithful for all eternity. They are likened to gold, silver, and precious stones.
(Eternal life is freely bestowed upon all who believe as a gift apart from the works, and cannot be forfeited.) The crowns however, can be earned and lost, accumulated and liquidated.
At the Judgment seat of Christ, He will present a number of “crowns” for specific service: 
The Watcher’s Crown (a crown of righteousness) given to all who longingly watch for Christ’s return.
The Runner’s Crown (an incorruptible crown) for all who strive for the mastery by keeping bodily appetites under control and being temperate in all things.
The Shepherd’s Crown (a crown of glory) reserved for faithful ministers.
The Soul-winner’s Crown (a crown of rejoicing) for those who bring others to the Savior.
The Sufferer’s Crown ( a crown of Life) for those who have suffered for the sake of Christ, and the gospel.