The book that we call Ephesians in our Bible was written by the Apostle Paul while he was in prison in Rome in the AD 60-62 time period. This imprisonment is recorded in
Acts 28.
Paul calls the folks there "saints" and "faithful) (
Eph 1:1) and refers to "God
our Father"(
Eph 1:2). In verses 13 and 14 of that first chapter he mentions that they had heard the gospel, had believed, and were sealed unto the day of redemption by the Holy Spirit.
We assume these folks were saved/born again of the Spirit and had the Holy Spirit (Spirit of Christ) dwelling within. In chapter 5 and verse 18 he encourages them to "be filled with the Spirit" or as some paraphrase it, "keep getting filled with the Spirit" or "be ongoingly or continuously filled with the Spirit."
The work of the Spirit begins in us when we are drawn to Jesus.
The Spirit then opens our hearts to Jesus.
When we make that surrender to Jesus He comes into our hearts to dwell as the Holy Spirit and we are:
born of the Spirit,
sealed by the Spirit unto the day of the redemption of the purchased possession,
baptized (placed) by the Holy Spirit into Christ or into the Body of Christ.
This, however, is not the last and final work of the Spirit in our lives.
After our born again or saved experience we are to walk in the Spirit and be filled with the Spirit and some day our mortal body will be transformed/resurrected by the Spirit.
Some of us here believe that the disciples of Jesus were saved and had their names written in Heaven before (
Luke 10:20) the Day of Pentecost recorded in Acts chapter 2. Before Jesus ascended He told them to wait in Jerusalem until they received an empowerment of the Spirit which He also referred to as a baptism in the Spirit (
Acts 1:4-8). Ten days later they received an experience which says they were "filled" with the Holy Spirit (
Acts 2:4). Peter referred to this experience as the Spirit being poured out (
Acts 2:17, 32). Later in
Acts 4:8 we read that Peter was filled with the Spirit, and still later he was among a group of people who were filled with the Spirit (
Acts 4:31).
So, there are experiences subsequent to being born of the Spirit when it speaks of the Spirit being poured out; the Spirit coming upon; receiving (making room for) the Spirit; being immersed/baptized/saturated in the Spirit; and being filled with the Spirit.