SPECIAL TOPIC: FRUIT OF THE SPIRIT

There are many different phrases which describe the ministry of the Spirit to believers:

the wooing of the Spirit (cf. John 6:44,65)
the baptism of the Spirit (cf. 1 Cor. 12:13)
the fruit of the Spirit (cf. Gal. 5:22-23)
the gifts of the Spirit (cf. 1 Cor. 12)
the filling of the Spirit (cf. Eph. 5:18)

To be full of the Spirit implies two things:

that the person is saved (cf. Rom. 8:9)
that the person is led by the Spirit (cf. Rom. 8:14)

It seems that one's "fullness" is related to one's continually being filled (PRESENT PASSIVE IMPERATIVE of Eph. 5:18). For "filled" see full note at Acts 5:17.