There are no careers in the Church. You don't become a worship team member because you can sing. You don't become a youth pastor because you have energy. You don't become a pastor because you are a good manager. You don't become a missionary because you like to travel. You don't become an evangelist because you like being the center of attention. Whatever you do in the Church is because God called you to that thing. If you chose your position you are in a lot of trouble.
As a member of the Body of Christ you must always be aware that God chose you for that place. Apostle Paul was always aware and kept reminding himself that he did not choose but was chosen:
I have become its servant by the commission God gave me to present to you the word of God in its fullness. (Colossians 1:25)
Paul is referring to being a servant to the Church. He was keenly aware that it was Jesus who gave him that responsibility and as such he dare not walk away from it. How did Paul find the strength to go through what he did to present the gospel to the world? It's amazing what you can go through when you know that Jesus chose you and is backing you up.
Paul often wrote on this subject, reminding people again and again that we do not get to decide what we are in the Body. It is not by our aptitude, talents or psychological profile; it is according to the will of God. Read in 1 Corinthians 12 the reminder that the Spirit chooses the spiritual gifts for us and it is God who appoints people to positions. Remember in general that Jesus told us that we did not choose him but he chose us. We have to remember that and take our proper place.
It is funny how I knew I was going to be a pastor even when I was lost in my rebellion as a teenager. Even though I had walked away from God, the church and anything to do with Jesus, I knew what my calling was. It wasn't that I had any talent for it. I was not a people person. I was not good at public speaking. I had nothing at all to offer, yet I knew what God had knit into me and what he had prepared for me to do. So here I am.
It is with this keen awareness that you never quit. No matter how difficult it gets, or how tired you become, or even how much discouragement you face, it is impossible to quit when you know you have been commissioned by God. A pastor can never walk away, no matter the cost, because it was God's choice not his. Paul could never quit. It was impossible for him. Even after jail time, beatings, stonings, shipwrecks and abandonment by those he trusted, Paul pushed through, because Jesus had chosen him.
If you can understand of what I am writing here then you understand the depth of God's calling. But if this means nothing to you and you have walked away from many things in your life, you should take a serious look at what you think you have been called to do.
There is one other thing about God's calling: It is irrevocable. Even if you failed to walk in it in the past; even if you failed in it; even if others consider you unworthy, the calling is never removed. If you were called to that thing 50 years ago and never responded to God, you are still called to it today:
As far as the gospel is concerned, they are enemies on your account; but as far as election is concerned, they are loved on account of the patriarchs, for God’s gifts and his call are irrevocable. (Romans 11:28-29)
So, time to take a good evaluation of what you are doing and why. Don't waste your life doing something that was not God's intention for you. Move back into his will and watch the strength and blessings flow in your calling.