YOU'VE BEEN CHOSEN!

From beginning man has been part of God's plan, even before the earth was created. You have been chosen by God. Ephesians 1 vs 4 "For he chose us in him before the creation of the world to be holy and blameless in his sight. In love"

The bible in 1 peter 12 vs 20, says that Christ was forordained before the foundations of the world but was made manifest in the last times for you and I. Revelations 13 vs 8 makes it clear that Christ was slain from the foundation of the world. You are probably wondering how this is related, you are the reason why that happened. God had a purpose for man before he made man, he wanted you to have an inheritance. You wouldn't be able to fulfill your purpose if Christ wasn't slained for you. For God to make you in his image says alot. This just shows you are special and loved by God.

PREDESTINATION
Before you were born, you existed in God's plan. He saw you. You were predestined and chosen for a purpose. No one on earth is a mistake, both the believers and unbelievers. You have a special place in God's heart. You were not born at the wrong time too. The very minute you came forth from the womb was planned. Jeremiah 1 vs 5
"Before I formed you in the belly I knew thee, and before thou camest forth out of the womb I sanctified thee, and I ordained  thee a prophet unto the nations".
God formed you just perfectly with all you need to fulfill your purpose.

QUALIFICATION/ORDINATION/CALLING
From Jeremiah 1 vs 5, We can see that we've already been sanctified (prepared, dedicated, consecrated, procliamed, equipped) for our callings before we were born.
You are not under qualified for it. Your calling is not too big for you, you are more than able for the task.  Read 1 Samuel 16 vs 7,10,12,13.
7 But the LORD said to Samuel, "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".
This was when Samuel thought the older, taller and bigger sons of Jesse were the ones called. Size, looks or age isn't a criteria for God. Jeremiah thought he was not qualified to fulfill his calling as a prophet but God is never too early or too late when he calls a man. If you feel too old he will give you vigour and renew your strength. If you feel too young, he will make you fearless and your words and actions will be more than that of a child. When God gives you the mantle, you can do anything. He will put the words in your mouth to speak and guide you on and when to speak. God calling you is him authorising you. Your calling is beyond your Job or degree. 

JUSTIFICATION/GLORIFICATION
Accepting Christ into your life makes you justified and righteous. Your calling can only be fulfilled or accomplished when you have Christ. The Holy spirit who is an evidence of your recipient of Christ guides, leads, teaches, encourages and comforts you in the course of your calling. He begins with you too. Without Christ you can do nothing. You may have been predestined for a purpose but if you don't receive Christ into your life you can't accomplish it.
John 15 vs 4-5
4 Remain in me, and I will remain in you. No branch can bear fruit by itself; it must remain in the vine. Neither can you bear fruit unless you remain in me.

5 "I am the vine; you are the branches. If a man remains in me and I in him, he will bear much fruit; apart from me you can do nothing.

John 15 vs 8
8 This is to my Father's glory, that you bear much fruit, showing yourselves to be my disciples.

Colosians 1 vs 27
27 To them God has chosen to make known among the Gentiles the glorious riches of this mystery, which is Christ in you, the hope of glory.
When you have Christ, the Glory of God is revealed in you.

 
If you feel you don't have a revelation of what your calling is, ask God to reveal to you and he will. Also, know you have what it takes. If you feel you are not going far enough in the area you were called to or you've been in your calling for years but nothing to show for it, hold on to God, pray for more of him and stay in his rest. Every journey starts from somewhere. Being called is a journey, you need to hold on to God patiently and let him take the wheel. John 15 vs 2a "Every branch in me that beareth not fruit, he taketh away". The greek word for "taketh away" in this context means to support, to lift up or take up, to strengthen, to bear and to anchor. God strengthens and supports you to become fruitful because that has been the plan from the beginning. 

 Never compare your journey to another person's, the calling might seem similar but trust me there's why yours is unique and requires you for the job. 

 When the time for Jesus to be crucified was nigh, while praying in the garden he prayed for the cup he was to drink to pass him according to the Father's will and the angel of the Lord appeared and strengthened him- Luke 22 vs 42-43. Days may come when you face some challenges or trials in the line of your calling just look up to God. If he called you to it he will see you through it. He is the one who sustains the throne. 

2 Timothy 4 vs 7

7 I have fought the good fight, I have finished the race, I have kept the faith.

8 Now there is in store for me the crown of righteousness, which the Lord, the righteous Judge, will award to me on that day--and not only to me, but also to all who have longed for his appearing.