I agree with most of what the others have said, and this is my experience.
I was raised in a Pentecostal Church of God (sister organization of the Assemblies of God). While in the organization, at four different times by different visiting evangelists, every time I went up for prayer the speaker would put their hand upon me to pray, stop for a moment, then pull their hands off me and tell me that God had called me into the ministry.
Later, after studying the Word of God for myself, weighing in the balance things taught to me through the PCOG, I felt that I could not remain associated with them because the truth is more important than anything else...people don't get saved by listening to false doctrine, they only produce people who think they are christians but are not. So I left the PCOG and, because people like to see paper as "evidence," I sought ordination through a reputable organization that wanted to know my qualifications and experience.
To me, (I am non-denominational) it is just a piece of paper. God called me and confirmed that calling several times for my sake, and for those who heard around me (I believe).
It is sad today that many of our pulpits in this country are filled by people who only have paper...and who were never called nor ordained by God. This is the reason why I believe so much false doctrine is spread throughout the church in this country today (America), because we have people who may well have been trained in seminaries as ministers, but if they are void of God's call, they have no business preaching or teaching as pastors. I am not saying that they cannot have God's Spirit and be able to do such things, but i believe there is a warning in scripture that God calls those who He wants to be His messengers, and they have a special anointing for the task where others (those who have not been called by Him) do not have.
Sorry, I rambled...