Our belief on the need for the Holy Spirit impacts other things we believe. In my experience, those who downplay (which means–never talk about) the Holy Spirit, also downplay the following biblical doctrines:
1) Prayer–the Holy Spirit is linked with prayer continually. If prayer is viewed as optional, doesn’t really do anything, or is merely saying the same words, then what need is there for the Holy Spirit?
2) Gifts–spiritual gifts are not natural talents but rather spiritually created desires and abilities, not seen until after spiritual rebirth. If there is no talk of spiritual gifts–all of them, not just tongues and healing–you’re probably in a church that minimizes the Spirit.
3) Fruit–If life is sort of just a thing that is in the way before heaven and there’s no real point for Christian living, if salvation is just the same life as before just with more church, then fruit is not big on your list and the Spirit is not big either.
4) Resurrection Life–living the new life in Christ means a cessation of your old life, you are dead and crucified. Therefore all you have left is the Spirit and His spiritual life. No emphasis on resurrection life? Then more than likely little talk of the need for the Spirit.
5) Scriptural Knowledge–sure, you may know your proof texts and you may have down all the verses your guys gave you, but you know little about the rest of the Bible and little concern to figure it out, then the Spirit does not rank highly. What’s the point of having The Teacher if we know it all already?