1 Corinthians 1:1-2 Paul, called as an apostle of Jesus Christ by the will of God, and Sosthenes our brother, to the church of God which is at Corinth, to those who have been sanctified in Christ Jesus, saints by calling, with all who in every place call on the name of our Lord Jesus Christ, their Lord and ours:
This is just one of the many places in scripture that explains that each of us are "called" for a purpose by the will of God. When we accept Jesus as our Lord and Savior, it is because the Holy Spirit has been working on our heart. God has been calling us - chosing us. It is nothing of ourselves. Do not think more highly of yourself because you are a Christian against someone who is not.
Once you have become a Christian, seek to know God's calling or will for your life. What is it that He wants to accomplish through you? Do not be afraid to ask Him what it is and after He tells you, do not be afraid to do it. You will enjoy abundant life when following God's perfect calling and will.