This is in fact a major component to our Gospel. Our sins are a huge deal because it separates us from God. However, God didn't solve our sin problem in order to leave us spiritual orphans. He solved our sin problem and then gives us his Holy Spirit in order that 1.) we may have an intimate relationship with him and 2.) empower us to actually walk in a manner that is pleasing to him. Without the power of the Holy Spirit, we are actually impotent or unable to obey and know God.
I assure you, people do not seek God, obey God, know God, etc. on their own. We need God to pursue us and do something within us...and this is what the Holy Spirit does. He enters our lives and begins to transform us into what God intended us to be. Bock states it a little more eloquently when he says, "Here is the Creator God reaching down to touch a rebellious people's heart through a sacrifice that He himself brings, so that those He created may experience the life they were originally designed to live--a life in harmony with creation because it is in accord with the Creator. The gospel is not about a death but a death that leads many into life."
Therefore, forgiveness of sins is a huge deal, but the gospel isn't merely about forgiveness. The point of forgiveness is to demonstrate that there is a huge chasm or barrier that stands between God and mankind and God solved that issue through his Son and by giving us His Spirit so that we can know and obey Him.