Written by the Apostle Paul to Timothy (1 Timothy 1:1) around A.D. 62-66. Paul wanted to encourage Timothy as he took care of the Ephesian church. This letter helps teach Timothy on how to organize the leadership and priesthood of the early church. It is in essence an administration manual.
The following was taken from here ( a church site) as reference to what will be covered.
Administration of the Church—Paul outlined qualifications for certain church leaders, especially bishops (1 Tim. 3:1–13). Important instructions were also given regarding the church’s responsibility to various classes of members within the church—the aged, the young, the widows—all of whom were to be treated with discretion according to their situation and needs (1 Tim. 5:1–20).
2. False Teachers and Apostasy—Corrupt teachers were, and would be, on the scene encouraging questions, doubting(s), disputations, and strife among the members (1 Tim. 6:3–10). Timothy was to avoid these teachers and teachings, and to warn the saints against such (1 Tim. 1:4–11, 1 Tim. 4:7, 1 Tim. 6:3–11, 17, 20).
3. An Example of Godliness—As a leader, Timothy was admonished to be “an example of the believers, in word, in conversation [conduct], in charity, in spirit, in faith, in purity” (1 Tim. 4:12). He was also to encourage the saints to “be rich in good works” (1 Tim. 6:18) and to live in a godly manner (1 Tim. 6:3).