What does Reformed theology say about the evidence of salvation?

In Reformed theology, the evidence of true salvation is rooted in the heart's condition and the presence of faith rather than external works or changes in behavior. The believer may struggle with sin more acutely after coming to faith, as the Holy Spirit opens their eyes to the reality of sin and the need for grace. This aligns with Romans 8:28-30, which outlines God's sovereign work in calling and justifying the elect. In contrast to other religions that provide outward markers for salvation, the believer finds assurance in the internal work of the Spirit, which produces authentic faith and dependence upon Christ's completed work.