What was every child of God before salvation?
Before salvation, every child of God was in the place of being a sinner—a son of Adam, condemned already. That is the universal starting point. Only after realizing that condition, hearing the gospel, and believing it does the Holy Spirit come in and seal the believer.
Les explains the progressiveness and order of salvation: after hearing the word of truth, the gospel of your salvation—Paul's gospel that Christ died for our sins, was buried, and rose again—and after believing, believers were sealed with the Holy Spirit of promise. Before that, every child of God had to come from being a sinner, a son of Adam, condemned already. As soon as we realize we are a sinner, we hear the gospel, the Holy Spirit opens our understanding, and we believe it. The moment we believe, the Holy Spirit comes in, becomes God's brand upon us, and becomes the power of God within us. This grace does not license lawlessness; believers are led and guided by the indwelling Holy Spirit.