To those who ask, 'Where then have you seen the gods? What conviction of their existence leads you to this worship of them?', I reply first that they are in fact visible to our eyes. Secondly, and notwithstanding, that I have not seen my own soul either, and yet I honour it. So it is with the gods too: from my every experience of their power time after time I am certain that they exist, and I revere them.
The salvation of life lies in seeing each object in its essence and its entirety, discerning both the material and the causal: in applying one's whole soul to doing right and speaking the truth. There remains only the enjoyment of living a linked succession of good deeds, with not the slightest gap between them.
Studying history, in my opinion, does more to help you realize how futile and worthless a large swath of life is. People pursuing power, riches, fame, immortality ... utterly useless and pointless. Where are the most powerful, the most famous, the most beautiful, the strongest? Where are they now? Dead. Dust. Forgotten.
Instead, how much wiser to spend your time and efforts to simply focus on justice, self-discipline and loving your lot in life? This leads to contentment and peace of mind.
Marcus believed in the gods. It helped him love his lot in life.
In chapter 29, Marcus summarizes what life is about.
1. seeing things as they really are (and not applying judgement to them).
2. ensuring all your actions and words are just; and going from one good deed and word to another.
(see also Citadel p. 41, 43, 48, 186, 239, 273)