In Acts 9:15, God calls Saul his instrument, his tool, for carrying his word to the non-Jews.
I have many tools in my work shop, and each one has a specific purpose. If I try to use a screwdriver to drive a nail, I will probably damage the screwdriver.
In like manner God has called Saul (Paul) into a specific ministry, which no one else is called to fill.
Each and every Christian is also called into some form of ministry. For some this may be into the ministry, into evangelism or into teaching, but for most Christians it is most likely a ...