—1 Corinthians 12:11-13 (NASB)
It seems to me that a lot of people turn to Paul's teachings on spiritual gifts — and to this chapter in particular — and treat it as some kind of "road map" for obtaining said gifts. Paul never ever provides a "how to" except to state that they're given by the Spirit "just as He wills". The greater context in which Paul is dealing with the Corinthians is the proper use of what they've already received. In spite of having been baptized in the Spirit and having received His gifts, this was a church with a lot of problems in the areas of idolatry, sexual immorality, division, grumbling, and so forth. Paul's not saying that these problems will be solved if they could somehow get the gifts, but that the problems persist because of their misapplication of them.
In the opening paragraphs of this letter to the Corinthians, Paul confirms that they have already received ALL the gifts.
—1 Corinthians 1:4-7 (NASB)
I think this is an important point because I've come across so many who seem to believe that if they can just obtain this or that spiritual gift, the problems in their life would be resolved. They seem to be missing the fact that having already been baptized by the Holy Spirit, assignments into the body of Christ have already been made. Certainly God is capable of bestowing additional blessings, but the real issue is whether or not we're living up to the calling and responsibilities of what we've already been given, the goal of that calling to work for the building up of everyone into "one body".
If you're not living a faithful, obedient life producing the fruit of the Spirit and helping to build the body as a whole, what use would it be for you to also gain the gift of miracles? If you're not walking faithfully, what additional benefit is there in also obtaining the gift of tongues? The only cure for faithlessness is faithfulness; the only cure for disobedience is obedience. Paul is addressing the problem of not properly applying what God has entrusted and using the very gifts of God for things other than their original, intended purpose.
The problem for most people today is exactly the same as it was back then. We don't need "more", we need to properly employ what's already been given. Until the heart is brought into proper subjection to God's Word and ways, no additional gifts, much less the ones we've already received, will make up for the lack of quality of our walk. It's the first step towards working to become "members of the body" instead of members unto our self.†††