1:1–3 - there is an interesting introduction here. Paul presents himself as a slave/servant of God, and an apostle of Christ.
Paul is in the service of faith of those elected by God to that faith. He also should make them know the meaning of godliness - worshiping God with one’s entire life (2 Tim 2:2; 3:16; 4:7.8; 6:3.5.6.11; 2 Tim 3:5).
The hope of eternal life can be connected either with faith, truth, or godliness. The hope of eternal life was promised by God “before times eternal” but it was revealed now through Paul’s preaching. This preaching is a command that comes from God.
1:5–9 - regarding those responsible for the community
Here, we have a glimpse on Paul’s method of work. (1) coming to a place and preaching the Gospel; (2) those who accepted the preaching formed a community. Paul spent with them some time and then moved on to another place, but he usually left that community in the hands of trustworthy disciple; (3) That disciple had a task to organize the community, particularly to select local leaders that would be responsible for growth of the community.
The requirements are similar to those in 1 Tim 3:2–7 - here it is a talk about elders - presbiters, whereas in 1 Tim 3:2 is talk about bishops - episkopoi. However in 1:7, the author uses the term episkopoi. It would indicate that terminology was not yet clearly defined.
It is worthy to notice the last requirement. He needs to hold fast to the word of faith that was taught to him. The word of faith, the doctrine, is passed from Jesus, to the apostles, to their disciples, and so on. Why is it so important? Only in this case, he can exhort those who also hold to true doctrine, and show the error to those who are opposing it.
1:10–16 - regarding false teachers
The false teachers particularly came from Christians of Jewish origins. According to Jospeh Flavius, we know that there was a big Jewish community in Crete. Apparently, they can overturn entire families - communities - with their teaching. It seems that they taught for material gain.
The problem is that false teaching has a negative impact on morality. Here, we have the connection between thought and action. The way we think influences the way we act. If we consider something to be true - even if it is not - we will act based on it. It seems that human person can easily get deceived. False teaching poisons our conscience. On the opposite side is good conscience led by mind enlightened with faith (2 Tim 1:3).
The quote comes from a Gentile poet living in 6th century before Christ, Epimenides. There was a verb “kretidzen” - which has the root for Crete and it means to lie. Thus, acting like a Cretenese would means to lie. Evil beasts tend to destroy what is established - in this case, sound teaching. Finally, idle gluttons - get ill gain profit.
Therefore, proclamation of the Gospel is so important. It teaches the truth, cleans our mind from wrong thinking and leads us to a right living. Titus supposed to reprove them for their own benefit, so they could persevere in true faith (1 Tim 1:10; 6:3).
The first step is to stop giving heed to Jewish fables - it is not clear what the author mean by it (1 Tim 1:4; 4:7; 6:20; 2 Tim 2:16; 2:21), but it seems it was a problem during that time, because it is mentioned often in pastoral letters.
1:15 - can also be found in Rom 14:14–20. It basically refers to the Jewish laws that distinguish between something clean and unclean, particularly in the matter of food.
The author probably builds on Jesus’ saying in Mk 7:15–16. If one’s heart is clean nothing can affect him, but if one’s heart is unclean everything he does will be affected. The basic idea is clear: it is one’s own conscience that affects our action. If this conscience is wrongly form, they way of life will also be wrong.
1:16 - Paul beautifully explained the above stated idea. Their claim of faith is contradicted by their actions (2 Tim 3:5). The tragic thing is that they are unfit for doing anything good.