Answer: We should be careful (and learn to) devote ourselves to doing good, because these things are excellent and profitable for everyone, (verse 8), AND in order that we may provide for daily necessities and not live unproductive lives, (verse 14).
MORE INFORMATION AND/OR OTHER SCRIPTURE REFERENCES:
See Question "a" above.
Below are examples of why devoting ourselves to doing good results in what is "excellent and profitable for everyone," providing for "daily necessities" and not living "unproductive lives":
Matthew 5:14-16: [Jesus said,] "You are the light of the world. A city on a hill cannot be hidden. Neither do people light a lamp and put it under a bowl. Instead they put it on its stand, and it gives light to everyone in the house. In the same way, let your light shine before men, that they may see your good deeds and praise your Father in heaven."
1 Timothy 2:9-10: "I also want women to dress modestly, with decency and propriety, not with braided hair or gold or pearls or expensive clothes, but with good deeds, appropriate for women who profess to worship God."
1 Timothy 5:9-10: "No widow may be put on the list of widows unless she is over sixty, has been faithful to her husband, and is well known for her good deeds, such as bringing up children, showing hospitality, washing the feet of the saints, helping those in trouble and devoting herself to all kinds of good deeds."
1 Timothy 5:24-25: "The sins of some men are obvious, reaching the place of judgment ahead of them; the sins of others trail behind them. In the same way, good deeds are obvious, and even those that are not cannot be hidden."
1 Timothy 6:17-19: "Command those who are rich in this present world not to be arrogant nor to put their hope in wealth, which is so uncertain, but to put their hope in God, Who richly provides us with everything for our enjoyment. Command them to do good, to be rich in good deeds, and to be generous and willing to share. In this way they will lay up treasure for themselves as a firm foundation for the coming age, so that they may take hold of the life that is truly life."
James 3:13-18: "Who is wise and understanding among you? Let him show it by his good life, by deeds done in the humility that comes from wisdom. But if you harbor bitter envy and selfish ambition in your hearts, do not boast about it or deny the truth. Such ‘wisdom' does not come down from heaven but is earthly, unspiritual, of the devil. For where you have envy and selfish ambition, there you find disorder and every evil practice. But the wisdom that comes from heaven is first of all pure; then peace-loving, considerate, submissive, full of mercy and good fruit, impartial and sincere. Peacemakers who sow in peace raise a harvest of righteousness."
1 Peter 2:11-12: "Dear friends, I urge you, as aliens and strangers in the world, to abstain from sinful desires, which war against your soul. Live such good lives among the pagans that, though they accuse you of doing wrong, they may see your good deeds and glorify God on the day He visits us."
