"From the apostle Paul and from all the Lord's followers with me. I was chosen to be an apostle by Jesus Christ and by God the Father, who raised him from death. No mere human chose or appointed me to this work." Galatians 1:1-2 CEVUK00
If God knocked me to the ground, blinded me and spoke to me, telling me what to do, then I guess I could say "I was chosen by Jesus Christ and by God the Father", but that didn't happen to me. I've been smacked to the ground plenty of times, but in every case God has used an agent to do so, rather than doing it personally.
The whole idea of a divine calling is bit sketchy to me. Some people think that I have abandoned my calling to do business. They will cite verses like "the gifts and calling of God are irrevocable" to say that if ever, you decide to be a full time pastor, then that is what you must do until the day you die. It is true, that I feel completely unworthy to serve as a pastor and the role of businessman is more comfortable. A businessman does not have to be perfect, but a pastor may not have feet of clay. I have feet of clay.
I don't think I will ever have the absolute confidence of Paul. All I have is this: Jesus said "Go and make disciples of all the nations ..." and I'm trying my best to obey Him. He said "all authority in heaven and on earth has been given to me (Christ)", so I don't need a personal calling - I have a command to obey. My calling, if you want to call it that, is to obey Jesus.