TRAINING

“AND THE KING APPOINTED FOR THEM A DAILY PROVISION OF THE KING'S DELICACIES and of the wine which he drank, AND THREE YEARS OF TRAINING FOR THEM, so that at the END of that time THEY MIGHT SERVE BEFORE THE KING .”
Daniel 1:5 (NKJV)

Trainings are required in any field of operation. It is only in the ministry work that you see the people claiming they have received a call and wanted to fulfil it without any training.
Nebuchadnezzar the king of Babylon required that the people appointed to serve in his palace should be trained for three years. If someone who wanted to work with an earthly king would need to be taught and trained, I do believe strongly that someone who wanted to work with the heavenly King—God of gods, LORD of lords—would also need to be taught and trained.
God will not work with a quack, neither would He put a novice to work: "NOT A NOVICE, LEST BEING PUFFED UP WITH PRIDE HE FALLS INTO THE SAME CONDEMNATION AS THE DEVIL" (1 Timothy 3:6).

Jesus taught and trained His disciples; they were exposed to both the formal training and informal training in their three and a half years of walking with Him on the surface of the earth (Acts 4:13).
God usually trains those who He wanted to use by Himself, however, He would want whoever called into the ministry work to submit himself or herself for trainings—both the formal and informal.
Sit at someone's feet to be taught and be exposed to the practical aspects of the work: "BUT YOU MUST CONTINUE IN THE THINGS YOU HAVE LEARNED AND BEING ASSURED OF, KNOWING FROM WHOM YOU HAVE LEARNED THEM" (2 Timothy 3:14).
God has ordained man to bless man (Hebrews 7:7). And God would not duplicate His efforts, whatever you needed to know in the ministry work has been taught to some people; God would want you to go to such persons and learn it from them: "AND THE THINGS THAT YOU [Timothy] HAVE HEARD FROM ME [Paul] AMONG MANY WITNESSES, COMMIT THESE TO FAITHFUL MEN WHO WILL BE ABLE TO TEACH OTHERS ALSO" (2 Timothy 2:2 NKJV).
God has mandated some people to put into the writing what He has taught them, that others in the body of Christ may learn: "WRITE THE THINGS WHICH YOU HAVE SEEN, AND THE THINGS WHICH ARE, AND THE THINGS WHICH WILL TAKE PLACE AFTER THIS" (Revelation 1:19).
Thus, God expects you to go for such material and equip yourself with them.
READ: Deuteronomy 27:8; Isaiah 8:1; Habakkuk 2:2

If you had the call of God on your life, or you were given a particular assignment to fulfil, you must have a strong passion or desire for knowledge. A heart to learn is one of the qualities that whoever wants to fulfil in his or her assignment should possess.
Therefore submit yourself for trainings: • Allow yourself to be taught, that you may fulfil whatever God has called or chosen you to do.
• Also lay your hand on the material of proven ministers who God has stirred your heart to follow: "STUDY AND DO YOUR BEST TO PRESENT YOURSELF TO GOD APPROVED, A WORKMAN [tested by trial] WHO HAS NO REASON TO BE ASHAMED, ACCURATELY HANDLING AND SKILLFULLY TEACHING THE WORD OF TRUTH" (2 Timothy 2:15 Amps).
Those things which God has told such authors to write are meant to be used: "FOR THE EQUIPPING OF THE SAINTS FOR THE WORK OF MINISTRY, FOR THE EDIFYING [building up] OF THE BODY OF CHRIST" (Ephesians 4:12).
Peace!