Hi Jash. I hope this enlightens you. It still might be subject to correction by a more knowledgeable Catholic:
The Atonement, I think, correlates more directly to Christ’s Sacrifice on Calvary, His Passion and Death - as a Victim; which as high priest He offered to the Father…This is our Salvation, which is deliverance from sin and its consequences - all sin and all its consequences.
The Resurrection is more of a confirmation of the truth about who Christ is, the fulfillment of His promises, and the promise of our own resurrection.
Catholics hold that immediately after death, we face a “particular judgement”, which precedes the final judgement - which includes the final resurrection on the last day where then our soul will be reunited with its body.
The Catholic doctrine of the particular judgment is this: that immediately after death the eternal destiny of each separated soul is decided by the just judgment of God
From article 366 of the Catechism of The Catholic Church:
366 The Church teaches that every spiritual soul is created immediately by God - it is not “produced” by the parents - and also that it is immortal: it does not perish when it separates from the body at death, and it will be reunited with the body at the final Resurrection.
Here are several other pertinent articles from the Catechism of the Catholic church:
654 The Paschal mystery has two aspects: by his death, Christ liberates us from sin; by his Resurrection, he opens for us the way to a new life. This new life is above all justification that reinstates us in God’s grace, “so that as Christ was raised from the dead by the glory of the Father, we too might walk in newness of life.” Justification consists in both victory over the death caused by sin and a new participation in grace. It brings about filial adoption so that men become Christ’s brethren, as Jesus himself called his disciples after his Resurrection: “Go and tell my brethren.” We are brethren not by nature, but by the gift of grace, because that adoptive filiation gains us a real share in the life of the only Son, which was fully revealed in his Resurrection.
655 Finally, Christ’s Resurrection - and the risen Christ himself is the principle and source of our future resurrection: “Christ has been raised from the dead, the first fruits of those who have fallen asleep. . . For as in Adam all die, so also in Christ shall all be made alive.” The risen Christ lives in the hearts of his faithful while they await that fulfillment . In Christ, Christians “have tasted. . . the powers of the age to come” and their lives are swept up by Christ into the heart of divine life, so that they may “live no longer for themselves but for him who for their sake died and was raised.”
If you click the link below, you can read from article 638-658 inclusively of the Catechism of The Catholic Church. That would provide you with a more complete answer.
God Bless you.
hismercy.ca/content/church_docs/catechism/p122a5p2.htm#640