Long before we thought of the word "cloud" as a euphemism for "server farm", people still took time to look up at the actual clouds and marvel at God's creation. In the Old Testament clouds are often signs of God's presence like the pilar of cloud that lead the people in Exodus or the cloud out of which God spoke.
Today as we begin chapter 12 of the Letter to the Hebrews, we are told that surrounding us is nefos martyron agkon, a cloud of many witnesses. In Chapter 11, our writer went all the way back to Abel and reminded us of all of the faithful of the Old Testament.
In the creed when we say Jesus "descended into hell" we are referring to the fact that before the resurrection no one went to heaven they all went to Sheol, the place of the dead. When Jesus died, he descended to Sheol, open the gates to allow the righteous from the beginning of time to now enter heaven, to spend eternity in the presence of God. All of these people form the cloud of many witnesses. Try and imagine the number.
And the Letter to the Hebrews reminds us that we live enveloped in this cloud. Add to this what St. Paul tells us about our bodies being a temple of the Holy Spirit and you have beautiful image of the Christian body, a beautiful temple with the light of the Holy Spirit shining inside it, completely surrounded by this innumerable cloud of witnesses, example of the faith.
How can Jesus expect so much from us? Because each of us is that temple. And we should not be afraid in prayer to reach out to the members of the cloud for guidance and support.