Simply put, our entrance into this eternal relationship is by (1) what God has done for us, (2) what God is doing for us and (3) what God will do for us. All three are accomplished through Jesus Christ.
The first facet of the gospel is the role of the life, death and resurrection of Jesus in our salvation. Without this there would be no means to reconcile us to God and begin the process of salvation. This is where most theologians place the emphasis, but often to the exclusion of two other important aspects. Many interpret this part of God's plan as the end of the salvation process. In reality it is only the starting point.
The second aspect flows from Christ's promise to send a "Helper," God's Spirit, to lead Christ's disciples into understanding and living by the truth of God (John 14:16-26). When one repents in faith and receives the gift of God's Spirit (Acts 2:38), he begins a Spirit-led life. Through His Spirit, as Paul explained, God "works in you both to will and to do for His good pleasure" (Philippians 2:13).
To help us gain salvation, Christ, as our High Priest, makes intercession for us at the right hand of the Father in heaven. Many passages in the book of Hebrews amplify this point. We are encouraged, "Let us therefore come boldly to the throne of grace, that we may obtain mercy and find grace to help in time of need" (Hebrews 4:16).
The third aspect of our relationship with God made possible through Jesus Christ is what will happen when Christ returns. At that time those "in Christ" (Romans 8:1), those with God's Spirit, will inherit the Kingdom of God—becoming immortal spirit beings in God's eternal family through the resurrection to eternal life (1 Corinthians 15:50-54). As kings and priests they will assist Christ in reigning over the nations (Revelation 5:10; Revelation 11:15).
Not one of these three aspects of the gospel should be emphasized over the other. Nor can any of the three be neglected without distorting the gospel taught by Jesus and His apostles. All three are essential elements of the gospel of the Kingdom of God.