And Ezra came to Jerusalem in the fifth month, which was in the seventh year of the king. On the first day of the first month he began his journey from Babylon, and on the first day of the fifth month he came to Jerusalem, according to the good hand of his God upon him. For Ezra had prepared his heart to seek the Law of the Lord, and to do it, and to teach statutes and ordinances in Israel. Ezra 7:8-10

Though the book of Ezra bears his name, Ezra did not arrive in Jerusalem for seven years since the beginning of Ezra chapter one.
When he made the journey, it took five months to travel from Babylon to Jerusalem.
Ezra did not go into this journey and work half-hearted but “prepared his heart to seek the Law of the Lord, and to do it, and to teach statutes and ordinances in Israel.”

As a minister, I cannot teach others God word without first preparing my heart to seek it.
I must say the same for any Sunday school teacher, VBS worker, Christian author, or someone that fills in on a Wednesday evening Bible study.
To witness to someone about the Gospel of Christ takes a preparation of your heart to give it.
When you involve yourself in the work of God you cannot do it half-hearted or flippantly. It is not a light switch to turn on and off when needed. It is a light you must let shine at all times. Just as the light needs a constant flow of electricity in order to shine, so a Christian must have a constant flow from the Holy Spirit in order to shine.