How does sin affect believers according to the Bible?

According to Romans 7, believers experience a continuous battle with sin due to the presence of the flesh, which still carries the corrupt nature inherited from Adam. While they desire to obey God, they find themselves struggling against sin that dwells within. However, the sermon reassures that such sin does not have dominion over believers, as ultimately, they are in Christ who has defeated sin and death. The struggle serves to remind them of their need for grace and reliance on the Spirit to live out their new identity in Christ, which confirms the reality of their regeneration.