Why do Christians struggle with sin despite being believers?

The struggle with sin for Christians is attributed to the presence of the 'old man' or the sinful nature that remains even after conversion. As described in the sermon, every believer carries this burden and faces daily temptations arising from their flesh. This reality is part of the Christian experience, as Paul highlights the ongoing battle between the flesh and the Spirit (Galatians 5:17). However, the key lies in recognizing that while we grapple with sin, the new birth provides the capability to identify and mourn over our sinfulness. Ultimately, the hope is found in the assurance that by God's grace, we can be victorious over sin as we rely on Christ's enabling power.