I read St. Seraphim's biography and purchased an icon of him many years ago, I believe even before seminary, and have returned to his teachings, and sought his prayers, for quite some time. Here is a short, simple saying of his which have guided me well for many years. 

This reminds me that my chief ministry as a Christian is to become someone in whom God dwells. My job is to be open and obedient; any fruit that I bear is much more dependent on this than on my talent, brilliant ideas, personal charisma or leadership abilities, etc. It's always about God-through-me, not about what I, in my own strength, can do for God. If I pursue God, everything else will work out. 

So how does one acquire the Holy Spirit? Fr. Seraphim would say that it is from thousands of small, daily acts of repentance, forgiveness, self-denial and active love - nothing mysterious at all, no secret formula for holiness, nor any short-cut to it. As Fr. Stephen Freeman puts it:

Grace is a gift. You don't have to go anywhere to get what you already have been given. What we need to do is allow the grace of God to work in us what God intends. Thus St. Paul urges: "We entreat you not to receive the grace of God in vain!" (2 Corinthians 6:1)