Paul evidently had opportunities to speak with those of the palace guard and even convert some of Caesar's household (cf. 4:22). For this he was thankful! All of those who took turns guarding Paul knew he was in prison because of his faith and not for any other reason. This surely made an impression upon them because he wasn't being held for a criminal act such as murder or treason.
Doesn't Paul have an attitude worthy of our imitation? He was able to see good in bad circumstances. You don't find him crying out in self-pity. Could you remain cheerful and optimistic while being held in prison unjustly? Would you be able to make an impact for good if you were in Paul's sandals?
Paul continued in Philippians 1:14 - "And most of the brethren in the Lord, having become confident by my chains, are much more bold to speak the word without fear." Paul's example of courage had helped his brethren to have more boldness in their preaching of the gospel. You might say that courage is contagious! This clearly shows the power of influence. Paul wasn't afraid to face persecution or prison or even death for the Lord. This encouraged others to do the same and not hold back out of fear.
Paul then goes on to state in 1:15-17 - "Some indeed preach Christ even from envy and strife, and some also from goodwill: The former preach Christ from selfish ambition, not sincerely, supposing to add affliction to my chains; but the latter out of love, knowing that I am appointed for the defense of the gospel." It should be observed that both groups of people Paul mentioned here are preachers of truth for they "preach Christ." False doctrine is not the issue here. The problem was the motive of these preachers. Some, sad to say, preached the truth with an improper motive; they preached out of envy and strife. Although we don't know the specific circumstances to which Paul referred, some scholars have speculated that perhaps there were some Judaizers who preached the gospel in that area for the sole purpose of stirring up the opposition against Paul. Other scholars have suggested that some brethren were jealous of Paul's reputation, and they were secretly pleased he was in prison so that they could steal the people's affection and build a reputation for themselves. Thankfully, there were others in the first century who did teach the truth from goodwill out of love.
"What then? Only that in every way, whether in pretense or in truth, Christ is preached; and in this I rejoice, yes, and will rejoice" (Phil. 1:18). Although Paul would rather that all who preached the truth do so from a pure heart, he was still joyful that the gospel was being faithfully proclaimed, period, even if it was by those who had ulterior motives. Now don't misunderstand. Paul did not say that those with the wrong attitudes were approved by God. He simply stated that he was pleased that the gospel was being spread.