The Gospel.
The Gospel is described in the 1689 London Baptist Confession of Faith as follows:
“…Since humanity brought itself under the curse of the law by its fall, it pleased the Lord to make a covenant of grace. In this covenant He freely offers sinners life and salvation through Jesus Christ. On their part He requires faith in Him, that they may be saved, and promises to give His Holy Spirit to all who are ordained to eternal life, to make them willing and able to believe…Only through the grace of this covenant have those saved from among the descendants of fallen Adam obtained life and blessed immortality.”
A man will be saved from the Hell and punishment his own sins have earned for him, if he repents, turning from his previous sinful life and ways, and believes in the power and sacrifice of Jesus Christ to save him. This is the fundamental, eternal truth of the Gospel and of our church.