Charles Finney emphasizes that dishonesty in small matters reflects a lack of true integrity in all aspects of life, arguing that one who is unjust in the least is unjust also in much. He explains that real honesty stems from a heart governed by love for God and neighbor, and that those who appear honest in larger matters may be motivated by selfishness rather than true principle. Finney illustrates this principle through various examples, showing that small acts of dishonesty reveal the true state of a person's heart and character. He warns that neglecting integrity in minor dealings can lead to a broader moral decay, ultimately undermining one's witness for Christ. The sermon calls for a commitment to honesty in all things, big and small, to reflect genuine faith.