"The people of God were always saved by grace through faith. Before the cross, God provided forgiveness based upon the work of Christ to come. And God circumcised the hearts of believing Israelites by his Spirit (Deut. 10:16; 30:6; Jer. 4:4; Acts 7:51; Rom. 2:28–29). So, Jesus’s death and resurrection did not bring salvation for the first time. Instead, his achievement was so great as to be the basis for salvation at any time in redemptive history. Similarly, Pentecost does not represent the beginning of the Holy Spirit’s work in the world. Instead, it represents the work of salvation in a grander and fuller way." (Peterson, Robert A. Salvation Accomplished by the Son: The Work of Christ. Wheaton, IL: Crossway, 2012. Print.)
Two items of note from this quote that struck me. First, the greatness of Christ's achievement surpasses all of our race's contemplation of the events. It was great enough to save those who came before His birth, and it is certainly the only hope for those after His death. We would do well to regularly consider the magnificence of this Savior and His great salvation. Second, when I consider that Pentecost initiated a "grander and fuller" salvation, I am humbled to think that Christ chose me to participate in that. Why me? Not only was I elected to be one of God's children, but his mercy and grace came in a more brilliantly stunning salvation. Incredible!