The quotation you allude to is
yet for us there is one God, the Father, from whom are all things and for whom we exist, and one Lord, Jesus Christ, through whom are all things and through whom we exist. (1 Corinthians 8:6)
The Greek word translated “through” has a wide range of meanings depending on context. So a possible interpretation of the passage is that God created everything and we live for him, while Jesus was the reason for the creation and the reason we can live eternally. In other words “through” here means something like “because of”.
An alternative but complimentary explanation is that the verse is comparing the different roles of God and Christ in two different creations. The phrase “all things” (Greek ta panta, the everythings) is used for both the “all things” of the Old Creation, and the “all things” of the New Creation in the NT, for example Col.1:16-18. This possibility is strengthened by the parallel poetic structure and the lack of verbs ‘came’ ‘live’:
“yet for us:
there is one God, the Father,
~ out of whom all things
~ and into whom we
and there is one Lord, Jesus Christ,
~ through whom all things
~ and through whom we”
This may be an early Christian poem or even from a hymn. The point is to show the comparison between the physical creation, the “all things” from/into God, and the life of the believer in the New Creation, new “all things”, through Christ.
We do not believe that Jesus existed before his birth, so he could not have been active in the physical creation of the world. See Did Jesus Christ really come down from Heaven? for further discussion.