Today is the feast of the Blessed Mother’s Assumption into Heaven, body and soul. Many Christians–and indeed many Catholics–struggle to understand this teaching. CUF has a Faith Fact on the Assumption which can be viewed here if you’re looking for a thorough discussion of the question.
No one obeys the Fourth Commandment of honoring father and mother more fully than Jesus, who is Son of God and Son of Mary. It is fitting that Jesus would uniquely honor His mother—truly the Mother of God—by preserving her from the corruption of the grave and by glorifying her body in heaven before the general resurrection of the body for all the other saints on the last day.
There is even a stronger connection between the Assumption and the Immaculate Conception. The key Scripture verse is Genesis 3:15, in which the Lord says that He will put enmity between Satan and the “woman,” who is identified as the Mother of the Redeemer. “Enmity” means “total opposition.” This verse foreshadows Mary’s participation in the absolute victory of her seed (Jesus) over Satan. . . .
By a special favor granted to her by her Lord and Savior, Mary indeed did triumph over sin in her Immaculate Conception. Corruption of the body is a result of original sin. Because Mary was preserved from original sin in her Immaculate Conception, and since she sustained the fullness of grace given to her by God (cf. Lk. 1:28), Our Lady could not have experienced the consequences of original sin. So Mary also triumphed over the bodily corruption of death in her glorious Assumption.