Broader theological connection
1 Corinthians 15:20–23
Christ, the firstfruits
20 But now Christ is risen from the dead, the firstfruits of them that sleep:
21 For by a man came death: and by a man the resurrection of the dead.
22 And as in Adam all die, so also in Christ all shall be made alive.
23 But every one in his own order: the firstfruits, Christ: then they that are of Christ, who have believed in his coming.
Douay–Rheims · Challoner revision · 1 Corinthians 15:20–23
Why this matters
Christ’s resurrection grounds the future resurrection of those who belong to him. The passage is not a description of Mary’s Assumption.