While much can be said regarding the theology and ramifications of God's call in one's life, the question herein addressed is "Who does God call to be a leader?"
God looks at the character of those He calls.
When God sent Samuel to anoint a king for Israel, He said to Samuel of Jesse's eldest son, "Do not consider his appearance or his height, for I have rejected him. The Lord does not look at the things man looks at. Man looks at the outward appearance, but the Lord looks at the heart" (1 Sam. 16:7).
When God laid out the qualifications for elders and deacons in the church (1 Tim. 3:1-13; Titus 1:7-9), integrity, faithfulness, and self-control were emphasized more than skill. Though these passages deal with specific positions of leadership, the character of any type of leader would be important to God.
When Jesus addressed the issue of who would be leaders among His disciples, He said "You know that the rulers of the Gentiles lord it over them, and their high officials exercise authority over them. Not so with you. Instead, whoever wants to become great among you must be your servant" (Matt. 20:25-26). A leader, according to Jesus, is a servant. A servant, as seen in Jesus' own example, has a heart of humility and a selfless attitude. (Phil. 2:5-8).
--- Be sure to cultivate and guard your heart. You will do what you are supposed to do when you are who you should be.
God can use people with or without the natural ability and proper background.
God can, and often chooses to, work with raw material. God prepares and empowers those He chooses to do His work so He does not need to call people into leadership who have the natural drive, training, or good models of leadership in their background. He does not need to use people who look the part or who are already popular.
"Brothers, think of what you were when you were called. Not many of you were wise by human standards; not many were influential; not many were of noble birth. But God chose the foolish things of the world to shame the wise; God chose the weak things of the world to shame the strong." (1 Cor. 1:26-27)
The disciples, who went on to be founding leaders of the church, were fishermen and tax-collectors by trade. They were not highly educated or from influential families. Some had strong, driven personalities but others did not.
--- Be careful not to limit God. Take Him at His word when He says, "My grace is sufficient for you, for my power is made perfect in weakness" (2 Cor. 12:9).
God prepares those He calls.
Joseph was sold into slavery and falsely imprisoned during which time he gained favor and rose to a position of prominence.
Moses grew up in Pharaoh's household and then spent 40 years as a fugitive before he was ready to lead the people out of Egypt.
Joshua served as Moses' servant to prepare him to take Moses' place.
David worked as a shepherd and then as a soldier under constant pursuit before taking the role of king.
The disciples spent three years with Jesus to prepare them to be the early leaders of the church but even still, before they were to go out on their own, they had to wait for the Holy Spirit to come upon them in power.
God uses life experiences to mold and shape leaders. God uses life experiences to develop perspectives and passions essential to the capacity of leadership to which He calls.
--- Be careful not to short-circuit this preparation time due to impatience. God's ways and timing are best.
God equips those He calls.
God will use the way He designed people by spiritual gifting and possibly personality temperament to steer them into what type of leader they should be.
- Visionary leaders tend to have the spiritual gift of leadership and/or faith and/or the more goal-oriented bent of the choleric (D of DISC) temperament.
- Administrative leaders tend to have the spiritual gift of administration and/or the discipline and resourcefulness of the choleric (D of DISC) or the organized efficiency of the phlegmatic (S of DISC) or the attention to detail of the melancholic (C of DISC).
- Shepherding leaders tend to have the spiritual gift of pastor and/or the people-oriented ways of the sanguine (I of DISC) or phlegmatic (S of DISC) temperaments.
A person could have a combination of the typical leadership gifts hence suggesting that God could want him/her to be involved in leadership capacities that require a blend of two or even the three types of leadership.
A person could have a spiritual gift that takes him/her into one type of leadership and a personality that enables him/her to do another type of leadership, suggesting that God could want him/her to be involved in leadership capacities that require a blend of two or even three types of leadership.
Whether by personality or gifting, God will equip people to lead how and where He calls.
--- Be aware of your God-given design. You will lead the best when you put all of who you are into all of who He is.