If you asked someone what book of the Bible has the earliest reference in time, they would probably say Genesis. After all, it starts: In the beginning God. They would be wrong. The Gospel of John has the earliest reference in time because he begins with In the beginning was the Word. Creation doesn’t happen until verse 3 in John and that is important.
Now for some grammar (I know you are jumping with joy). The verb “was” here is in the imperfect tense which focuses on continual existence in past time. So John is making a profoundly deep statement. The Word (which John will directly tell us is Christ in 1.14) existed before creation in eternity past with God. Indeed, John will use the verb “to be” very carefully in the prologue to denote an existence outside the bounds of time. We can contrast that with his use of the verb (to become) which denotes something that had “come to pass in space and time” (as one commentator puts it).
With the magic of Logos Bible software, I’ve thrown a visual filter on the text so you can see what I mean. Green is the verb “to be” (eimi in Greek) and orange is the verb “to become” (egeneto in the Greek). For one good example of how careful John is, notice the difference between verse 1 and vs. 14. In vs. 1, In the beginning was the Word – Eimi, to be, existence out of and before time. In vs. 14, however, And the Word became flesh – Egeneto, to become, existence in space and time.
Christ existed outside of space and time before creation he “was,” but then he existed within space and time when he “became flesh.”