God gave His Son, the Son gave His life, and we receive all the benefits!
By mutual consent, the Father and Son made a covenant to keep and preserve the seed of Christ. It is meant to ensure that we will endure to the end.
“He shall cry to Me, ‘You are my Father, my God, and the rock of my salvation.’ Also I will make him My firstborn, the highest of the kings of the earth. My mercy I will keep for him forever, and My covenant shall stand firm with him. His seed also I will make to endure forever, and his throne as the days of heaven. If his sons forsake My law and do not walk in My judgments, if they break My statutes and do not keep My commandments, then I will visit their transgression with the rod, and their iniquity with stripes. Nevertheless My lovingkindness I will not utterly take from him, nor allow My faithfulness to fail. My covenant I will not break, nor alter the word that has gone out of My lips. Once I have sworn by My holiness; I will not lie to David: His seed shall endure forever, and his throne as the sun before Me” (Psalm 89:26–36).
The Father made this covenant pledge to His Son: “I, the Lord, have called You in righteousness, and will hold Your hand; I will keep You and give You as a covenant to the people, as a light to the Gentiles” (Isaiah 42:6). God was saying, “My hand will always be holding on to Yours and You will never be away from my keeping power. I pledge to keep You safe from all the schemes of the devil.”
This pledge by the Father is made available to us now because the Son’s sacrifice on the cross has brought us into their covenant agreement. God pledged to His Son, “If You go, I will keep and preserve every one of Your seed, just as I have kept and preserved You. I will never remove My faithfulness from You, nor from Your children.”