Heb 12:1-2 calls us to look to Jesus to see how we are to run with endurance the race of following Christ. Heb 12:2 says we are to look to  "to Jesus, the founder and perfector of our faith, who for the joy that was set before him endured the cross." The key to understanding how to endure in our walk with Christ is looking to see how our Lord lived out His life. And what the writer of Hebrews tells us is that our Lord set his gaze, his focus, beyond the deepest, most tremendous suffering he was to endure: the suffering of the cross.

This becomes the key for us on how to "lay aside every weight and sin which clings so closely" and to "run with endurance the race that is set before us." We must set our focus on the reward that lies at the end in order to endure through the suffering that at some point will be required of us. That is, we need to see that when we are called to suffer not because of our sin -- for some of our suffering we bring to ourselves because we rebel against God -- but suffering because we are following Christ, we must not dwell upon and let our thoughts linger upon the suffering, but set our gaze and focus on the joy of being with God himself. (Matt 25:21,23; Rev 21:3-4)

The way to "lay an ax at the root of self-pity" that comes in suffering is to set our focus and gaze on the joy set before us, the joy of being with God!