Charles Finney emphasizes the importance of fearing the Lord and trusting Him even when one walks in darkness. He explains that this darkness is not a result of disobedience or guilt, but rather a period of spiritual trial where God's presence feels absent. Finney encourages believers to maintain a filial fear of God, which fosters obedience, and to trust in His goodness and wisdom despite their circumstances. He illustrates this with the examples of Job and Abraham, who exemplified unwavering faith in the face of profound darkness, ultimately leading to divine manifestation and growth in their faith.