Faith in Christ brings eternal life. Unbelief brings judgment. This framework is sin, righteousness, and judgment. These clarify and amplify the core gospel. Sin clarifies the need.
Righteousness clarifies the standard and the source of the solution.
Judgment clarifies the alternative if the righteousness of Christ through faith does not replace sin and guilt. Therefore, witnessing should emphasize the correct gospel content. We should communicate the core gospel and explain in within the gospel framework that the Holy Spirit uses. This may seem an unnecessary caution, yet much of so-called evangelism communicates an unclear or wrong gospel. Conviction is the work of the Holy Spirit.