The fact that Jesus ascended into heaven is only possible if Jesus had first descended.
NAU Ephesians 4:9 (Now this expression, "He ascended," what does it mean except that He also had descended into the lower parts of the earth?
There are two interpretations of ‘descended’. One more novel interpretation suggests that the ‘descent’ refers to the coming of the Holy Spirit. It means that if Christ ascended then he also must descend to give gifts in the Spirit. This is interesting but ultimately not the most faithful. While the view is very nuanced, verse 10 seems clear ‘He who descended is He who ascended’. The subject is Christ not Christ and the Spirit. Second, the traditional view is that Christ can only have ascended into heaven if He first descended. The grammar and word order, particularly of verse 10, make this the most likely.
Notice that Paul says “He who descended is Himself also He who ascended.” (o` kataba.j auvto,j evstin kai. o` avnaba.j). Some are quick to point out the unity of the work of Christ and the Spirit (1:13 with 4:30 and 1:23 with 5:18). Certainly the work of Christ and the work of the Spirit cannot be separated. In Pauline theology, Christ is a ‘life-giving Spirit’ who as the exalted second Adam, imparts the Spirit. This bears deeper reflection yet this is not the main point of Paul in Ephesians 4:9. Aside from Spiritual gifts and Christ’s grace giving the gift, the ‘Spirit’ is not the direct referent in the passage. The focus is what happened to Christ and what Christ has done. The most logical way to read the passage that read the least amount into this particular verse is to see Christ as the one who descended first before He descended. There is of course much Biblical reflection on the linking between Christ’s ascent and descent.
John 3:13 13 "No one has ascended into heaven, but He who descended from heaven: the Son of Man.
There are in the Old Testament and in Second Temple Literature people who ascend into heaven: Enoch, Moses, Elijah, etc. However, the NT associates Christ’s ascent closely with His descent because of the uniqueness of His person. They do not primarily see Him as a mere man who ascend, like the paradigm of exalted figures in Second Temple Judaism. Of course, Christ’s ascension is in full humanity… but this one who became fully human was nonetheless true God—He was identified as part of the divine identity (cf. Richard Bauckham’s God Crucified).
There are two views for interpreting “lower parts of the earth”. One view suggests that the ‘lower parts of the earth’ refers to Hades or Hell—somewhere ‘under earth’. This interpretation was quite popular in some of the church fathers. It means that Christ could not ascend until He had first gone into hell. Some then viewed Jesus as leading captives out of hell in redemption. The grammar here is not in favor of this interpretation. The text here ‘earth’ is a ‘genitive of apposition’. Simply put, the word “earth” examples the phrase “lower parts”. Paul means that Jesus descended to the ‘lower parts, namely the earth’. The lower parts to which Jesus descended is the earth itself. The focus is Christ’s humiliation—which is the incarnation and His death. God the Father did not exalt Christ until after He had descended.