John was filled with the Spirit in the womb, and would drink no wine (Luke 2:15), a Nazirite vow. Shadows of this Nazirite vow show up in Ephesians 5:18, “And do not be drunk with wine…but be filled with the Spirit.” In essence Paul is saying: Don’t be overcome w wine so you can be overcome with the Spirit.
To be “filled” with the Spirit is like a man who is filled with rage or filled with ambition. It means to be overcome by the Spirit. Nothing is to distract us from that. Believers are Christ’s Nazirites, so to speak, allowing nothing to overcome them but the Spirit. Only the Lord is to master us.