A - Thanks for the question. The simple answer is neither (in ordinary circumstances). While we consider the Incarnation, life, suffering, death, Resurrection, and Ascension of Christ one salvific act; the salvation of souls was not possible for all until Christ ascended into Heaven. Yet, each part of Christ's life is indispensable for our salvation:
A short summary of the parts of Christ saving us might help, note that this is not the full story of what each of these do for us:
- The Incarnation - When God takes on flesh in order to lower Himself to our state. This is the beginning of the Redemption of humanity and shows the great desire God has to save us.
- The Life of Christ - God offers us the example and teaching we need to know Him personally. He reveals Himself and His plan to us through the person of Jesus Christ.
- The Suffering of Christ - Christ takes on our sin to bring meaning to our personal suffering when combined with His. His suffering is for our redemption.
- The Death of Christ - Christ sacrifices his life for our eternal lives. He pays the price for our sin and liberates us from the bond of sin.
- The Resurrection of Christ - Christ defeats death by showing it has no power over Him. By His grace we can now have eternal life.
- The Ascension of Christ - Christ opens the gates of Heaven for us all.
On His part, in regard to those things which, in ascending, He did for our salvation. First, He prepared the way for our ascent into heaven, according to His own saying (John 14:2): "I go to prepare a place for you," and the words of Micheas (2:13), "He shall go up that shall open the way before them." For since He is our Head the members must follow whither the Head has gone: hence He said (John 14:3): "That where I am, you also may be." In sign whereof He took to heaven the souls of the saints delivered from hell, according to Psalm 67:19 (Cf. Ephesians 4:8): "Ascending on high, He led captivity captive," because He took with Him to heaven those who had been held captives by the devil--to heaven, as to a place strange to human nature. captives in deed of a happy taking, since they were acquired by His victory.The reason I said "ordinary circumstances", is that there were exceptions to this rule (e.g. the thief on the cross).
Secondly, because as the high-priest under the Old Testament entered the holy place to stand before God for the people, so also Christ entered heaven "to make intercession for us," as is said in Hebrews 7:25. Because the very showing of Himself in the human nature which He took with Him to heaven is a pleading for us. so that for the very reason that God so exalted human nature in Christ, He may take pity on them for whom the Son of God took human nature. Thirdly, that being established in His heavenly seat as God and Lord, He might send down gifts upon men, according to Ephesians 4:10: "He ascended above all the heavens, that He might fill all things," that is, "with His gifts," according to the gloss.
Thank you Christ for saving us!