"But by the grace of God I am what I am, and His grace toward me did not prove vain; but I labored even more than all of them, yet not I, but the grace of God with me." (1 Corinthians 15:10)
Grace is at the heart of who we are in God and what we have been called and energized to do. While not everyone will achieve to all God has for them, for those who do, and in whatever measure they do, the credit belongs entirely to God. Paul understood this and reflected it in many of his writings. Speaking of his own calling into service He wrote,
"But when God, who had set me apart even from my mother's womb and called me through His grace, was pleased to reveal His Son in me so that I might preach Him among the Gentiles, I did not immediately consult with flesh and blood" (Galatians 1:15-16)
Paul was not a "self-made" man, he was a "God-made" man. God had chosen even before his birth, before he had done anything good or evil, chosen based solely on the grace or favor of God. God has also chosen him for a specific place, time, and people. Nothing in regard to his selection was based on himself; who he was, his qualifications, his piety, his drive or anything else. He was chosen, gifted, and called because God willed it; it was simply the grace and favor of God for his live.
It is the grace of God that is the determinate of who we are and of our role and function within the Body of Christ. Paul writes,
"But to each one of us grace was given according to the measure of Christ's gift." (Ephesians 4:7)
This verse is in the context where Paul was describing the "one hope of your calling; one Lord, one faith, one baptism, one God and Father of all." (Ephesians 4:4-6) Paul begins by talking about sameness and oneness, but now he speaks of that which is different among us; God's grace and his giftings and calling in our life. We are not all meant to be the same, we are all different because of the different quality of the favor of God on our lives. Paul wrote,
"Since we have gifts that differ according to the grace given to us, each of us is to exercise them accordingly." (Romans 12:6)
We each differ from one another according to God's favor and His giftings in our lives. Understanding this we should not seek to mimic others in their grace and gifts but rather to be content in the grace and gifts given to us by God. Paul said of himself,
"According to the grace of God which was given to me, like a wise master builder I laid a foundation, and another is building on it. But each man must be careful how he builds on it." (1 Corinthians 3:10)
Paul was called as a wise master builder, but we may not be so called. Paul was called to lay a foundation but we may be called to build on the foundation. Our responsibility is not to try and imitate someone else but rather to find how for what purpose and function God has called us and to give ourselves to that calling in both action and thankfulness.
Finally, when we find God's purpose for our lives and begin to execute that purpose, we fine new boldness and authority in God; an authority that does not come from office or position but from the very commission of God on our lives. Paul write to the Romans saying,
"For through the grace given to me I say to everyone among you not to think more highly of himself than he ought to think; but to think so as to have sound judgment, as God has allotted to each a measure of faith." (Romans 12:3)
It's interesting that in a verse where Paul is urging humility he can speak with such boldness and authority. However, when we understand that we are who we are by the grace of God, and not of our own doing, we can express both humility and authority at the same time because our authority is not from ourselves but from God. Paul goes on to say,
"But I have written very boldly to you on some points so as to remind you again, because of the grace that was given me from God, to be a minister of Christ Jesus to the Gentiles, ministering as a priest the gospel of God, so that my offering of the Gentiles may become acceptable, sanctified by the Holy Spirit." (Romans 15:15-16)
Paul had great confidence and boldness in his giftings and authority in God because he knew it did not come from him, he who wast the "chief of sinners" (Titus 1:15), but from God. In the same way we too should have boldness and confidence in our role and function within the Body of Christ; not shrinking back, but using the things God has given us to serve others.
"As each one has received a special gift, employ it in serving one another as good stewards of the manifold grace of God." (1 Peter 4:10)