What is the Christian life compared to?
The believer's life is like paddling a canoe up a roaring river—never easy, but a constant battle against Satan's forces and the world's designs. God has promised believers can do it, so they work to further God's work and gain reward.
Les explains that the Christian life is like paddling a canoe up a roaring river. He says that would be pretty near impossible for him, illustrating that the Christian life is never easy; it is a constant battle. Believers are up against all the forces of Satan and all the designs of the world around them, but God has promised that they can do it. In the surrounding context, this connects with working to further God's work and gain reward, and with the reminder that God looks at the motivation—whether our work is gold, silver, and precious stones or wood, hay, and stubble.