I've been collecting funeral readings for a while... these aren't all strictly EA related, but do fit the science-y/humanist bent which seems to be common to EA culture:

'Do Not Go Gentle Into That Good Night' by Dylan Thomas- a fairly common/traditional funeral reading that fits in nicely with EA ideas about fighting back against death and metaphorical darkness.

'If I Can Stop One Heart from Breaking' by Emily Dickinson- doesn't quite fit the EA focus on having a large impact, but does line up well with the broader idea of doing good being a central focus of your life

'You Want a Physicist to Speak at Your Funeral' by Aaron Freeman- not obviously EA aligned, but still worth an honourable mention IMO, given the focus on embracing truth and reality

This passage from 'Unweaving the Rainbow' also seems appropriate, (though anti-natalists/those who believe human lives are net-negative may not agree with the sentiment):

We are going to die, and that makes us the lucky ones. Most people are never going to die because they are never going to be born. The potential people who could have been here in my place but who will in fact never see the light of day outnumber the sand grains of Arabia…Certainly those unborn ghosts include greater poets than Keats, scientists greater than Newton. We know this because the set of possible people allowed by our DNA so massively exceeds the set of actual people. In the teeth of these stupefying odds it is you and I, in our ordinariness, that are here

There's been some discussion of the EA-esque themes in George Eliot's 'Middlemarch' on the Forum (here and here). Various quotes from the novel seem as if they could work as readings. I'll highlight just a few...

For a graduation, there's this passage about pursuing knowledge/learning/education, not for its own sake, but to help us do good:

It would be a great mistake to suppose that Dorothea would have cared about any share in ... learning as mere accomplishment; for though opinion ... had pronounced her clever, that epithet would not have described her to circles in whose more precise vocabulary cleverness implies mere aptitude for knowing and doing, apart from character. All her eagerness for acquirement lay within that full current of sympathetic motive in which her ideas and impulses were habitually swept along. She did not want to deck herself with knowledge—to wear it loose from the nerves and blood that fed her action; and if she had written a book she must have done it as Saint Theresa did, under the command of an authority that constrained her conscience. But something she yearned for by which her life might be filled with action at once rational and ardent; and since the time was gone by for guiding visions and spiritual directors, since prayer heightened yearning but not instruction, what lamp was there but knowledge?

For a wedding, or a more general EA event:

What do we live for, if not to make life less difficult to each other?

This passage seems suited to a funeral, though could also be used more generally... it touches on the importance of shaping society to enable people to do good, as well as on celebrating the good we do manage to achieve, even if we don't have as much impact as we might have liked:

Certainly those determining acts of her life were not ideally beautiful. They were the mixed result of young and noble impulse struggling amidst the conditions of an imperfect social state, in which great feelings will often take the aspect of error, and great faith the aspect of illusion. For there is no creature whose inward being is so strong that it is not greatly determined by what lies outside it. A new Theresa will hardly have the opportunity of reforming a conventual life, any more than a new Antigone will spend her heroic piety in daring all for the sake of a brother’s burial: the medium in which their ardent deeds took shape is forever gone. But we insignificant people with our daily words and acts are preparing the lives of many Dorotheas, some of which may present a far sadder sacrifice than that of the Dorothea whose story we know.

Her finely touched spirit had still its fine issues, though they were not widely visible. Her full nature, like that river of which Cyrus broke the strength, spent itself in channels which had no great name on the earth. But the effect of her being on those around her was incalculably diffusive: for the growing good of the world is partly dependent on unhistoric acts; and that things are not so ill with you and me as they might have been, is half owing to the number who lived faithfully a hidden life, and rest in unvisited tombs.

Not sure how it becomes a speech, but anyone planning an EA wedding would probably be glad to read:

https://theunitofcaring.tumblr.com/post/190595156201/life-update-the-night-i-decided-i-was-going-to

I feel obligated to drop this link: https://secularsolstice.github.io/lists/gen/All_Speeches.html

Some of which could probably be adapted for non-Solstice purposes.