πρὸς τὸν θεόν: "with God"

Says In 1:1b and 1:2, πρός (pros) + accusative follows the stative verb ἦν. In Koine, πρός with a person after a verb of being often means simply "with, in the company of." It is close to παρά + dative and does not require motion. Compare Mark 6:3 (his sisters are πρὸς ἡμᾶς, "here with us") and 1 John 1:2 (the life ἥτις ἦν πρὸς τὸν πατέρα, "which was with the Father").

Says τὸν θεόν is articular.

Implies In the prologue it refers to the one John later calls "the Father" (1:14, 18; cf. 1 John 1:2). The Word is placed with this God, so the two are distinguishable.

Implies Read with 1:1c, the phrase gives personal distinction within the one God, a distinction that existed "in the beginning," before creation (1:3).

Uncertain Some interpreters press a dynamic sense, "toward" or "face to face with," as a picture of intimate fellowship. Koine usage after εἰμί does not demand it, so the team does not build on it. The intimacy itself is affirmed in 1:18 (εἰς τὸν κόλπον τοῦ πατρός).