Hebrews 12:1 Wherefore seeing we also are compassed about with so great a cloud of witnesses, let us lay aside every weight, and the sin which doth so easily beset us, and let us run with patience the race that is set before us,
2 Looking unto Jesus the author and finisher of our faith; who for the joy that was set before him endured the cross, despising the shame, and is set down at the right hand of the throne of God.
3 For consider him that endured such contradiction of sinners against himself, lest ye be wearied and faint in your minds.
Who are the cloud of witnesses?
What is the race that is set before us?
In context, the cloud of witnesses are the Old Testament saints listed in the gallery of faith of Hebrews 11. Certainly, today, the gallery of faith includes thousands of New Testament saints, from Stephen and James the apostle whose martyrdoms were counted in the book of Acts, to all those chosen by God who have been saved from then to now.
It appears that God lets them watch or get information on the news channels of heaven, as to how we're doing as we run the race set before us. Knowing that there's a cloud of witnesses watching us, gives us additional motivation to strive to run the race as we ought, realizing that these witnesses want to see us win, and are not watching to see us stumble!
The important person in this cloud of witnesses, is, of course, our beloved Savior, Jesus, Who is the most interested in our progress, and the greatest Encourager of all. He is the source (Author) of our faith, and the One Who will bring it to perfection (Finisher).
What then is the race that is set before us? Our lives of course, which are to be lived in faith, hope and love, and also in which we are to pursue the general and specific missions that God has given us.
Some of these missions apply to all believers. For instance, we are all called to be witnesses, and for the older to teach the younger and set the right example. We are also all called to worship the Lord in spirit and in truth, to feed on His Word, etc.
Other missions are specific. We can identify them by looking at the gifts and talents we have. When God makes a typewriter, He expects it to type; when He makes a piano, He expects it to play music. Looking at what God has endowed us with, both in the natural and in the spiritual, we will become aware of what He has made us for. We ought to be pursuing those missions. (In terms of the parable of the talents, we should be putting our talents to use, and grow them to greater strength and effectiveness in serving the Master.)
Not only because we have to give an account (which we have to), but also because there's an encouraging cloud of witnesses watching us use these talents, run this race, live this life for the God, and His Kingdom and eager to welcome us into heaven's realm when our time has come..