I believe that what the Bible teaches about human sin and salvation is true, and, that the Reformed Confessions are the most clear, complete and honest condensations of this teaching in existence. I fully accept that our Confessions are of human origin, and, are thus subject to change. However, I also know that many of them have stood the test of time, delivering comfort and clarity to Christians for centuries and even millennia. The fact that they are currently unappreciated in no way diminishes their intrinsic value.
So, faced with the challenge of summarizing what the Bible teaches about sin and salvation my first response is to look to our Confessions. For example, the Heidelberg Catechism explains sin and salvation as follows.
60. How are you righteous before God?
Only by true faith in Jesus Christ. In spite of the fact that my conscience accuses me that I have grievously sinned against all the commandments of God, and have not kept any one of them, and that I am still ever prone to all that is evil, nevertheless, God, without any merit of my own, out of pure grace, grants me the benefits of the perfect expiation of Christ, imputing to me his righteousness and holiness as if I had never committed a single sin or had ever been sinful, having fulfilled myself all the obedience which Christ has carried out for me, if only I accept such favor with a trusting heart.
Expiation: the act of making atonement
Impute: to attribute or ascribe
Thus, this answer says that, even though we sin, God, by an act of sheer grace choses to ascribe the perfect obedience of Jesus Christ to us. We are therefore “in Christ,” and when God sees us He sees not our sin but Christ’s perfection.
Lakes of ink have been drained considering this doctrine. It is beyond the scope of this work to address it in detail (although I did make my own attempt in God’s Acts of Providence). However, you should ask yourself one question, that being, “What if it is true that we are completely dead in sin and thus can only be rescued by a sovereign act of God?”