Whatever your hand finds to do, do it with all your might, for you are only passing this way once, and you might as well give it your best shot. This is the idea, stated in modern terminology, that Solomon was trying to get across in Ecclesiastes 9:10. It is also a godly trait.
Our Creator wants us to be wholehearted, or have singleness of heart in everything we do (Acts 2:46; Eph. 6:5; Col. 3:22). He wants us to be single-minded, with one purpose (Matt. 6:22; Luke 11:34).
The key to singleness of eye, singleness of heart and singleness of purpose is in serving other people and helping them be successful. That is why our Lord said that the greatest among you will be a servant to his brothers (Matt. 23:11). "Let no one seek his own good, but the good of his neighbor" (1 Cor. 10:24).
Jesus Christ, our example, taught people how to completely come out of self and become totally unselfish. He called all 12 disciples together and told them the way to become first in the kingdom is to be servants of all (Mark 9:35). Give it your all! Give it your best shot! Jesus used the strongest word He could when He said to be a "slave" to all (Mark 10:44).
Jesus did not come to be served, but to serve others for the glory of God (Mark 10:45). He did this wholeheartedly to the point of dying for us. He wants us to take the message of being a servant of others for the glory of God soberly. We are to have the attitude Jesus Christ had (Phil. 2:5, 7). We are to abide by His teachings and walk as He walked (1 John 2:6).
So, whatever your hand finds to do, seriously, do it with your whole heart, knowing that it pleases your Creator when you put your brother’s welfare first, before your own. Do all that you do in the name of Christ, as all disciples of Jesus Christ are commanded to do (Col. 3:17).