This can be stated in active form. Possible meanings: 1) The word "by" here indicates causality or secondary agency. Alternate translation: "For it was by means of Christ that God created all things" 2) The word "by" indicates instrumentality. Alternate translation: "God caused Christ to create all things" (See: [[rc://en/ta/man/translate/figs-activepassive]])
This can be stated in active form. God caused the Son to create all things for the Son's glory and benefit. Alternate translation: "by him and for him God created all things" or "God caused him to create all things for his own benefit" (See: [[rc://en/ta/man/translate/figs-activepassive]])