John Nelson Darby discusses the struggle between the law and sin, emphasizing that the law reveals our inability to overcome sin on our own. He explains that true freedom comes from being 'in Christ Jesus,' where believers are no longer slaves to sin but are forgiven and justified through Christ's sacrifice. Darby highlights the distinction between imputation and forgiveness, asserting that believers can approach God boldly without the burden of guilt due to Christ's atonement. He also addresses the role of priesthood and advocacy, clarifying that while believers may sin, they have an advocate in Christ who intercedes for them. Ultimately, Darby encourages believers to understand their standing before God and the importance of confession and holiness in their walk of faith.