The following is an excerpt from The Holy Spirit: Shy Member of the Trinity by Frederick Dale Brunner.
“I have become convinced that those persons are most filled with the Holy Spirit who are least conscious of it; all they know is that they wish to serve Jesus Christ, and they fell that they are unprofitable servants.” I think this means that if you and I are Christians who want to believe and obey the Jesus Christ of Scripture in the world of today, and if you and I are seriously discontented with our faith and obedience and long to be better Christians, we are not devoid of the Spirit, but we are actually filled with the Spirit. Being filled with the Spirit is often a different thing than feeling filled…wanting to serve Christ well [is] itself the great evidence of the filling of the Spirit. This is good news, since our normal sense of self as Christians – I think I can speak for most of us – is a sense of great inadequacy…It is a relief to know, is it not, that we can be normal, struggling Christian men and women and still be filled with the Spirit.
That he is God, coeternal with the Father and the Son, and that God grants him irrevocably to all who believe.