Don’t be an evangelist. More precisely, don’t be a tech evangelist.
Without taking a religious position of any sort in this post, I’ll point out that the term has some particularly strong associations for most people, whether good or bad. Christians see an “evangelist” as someone talking about the big questions in life from a particular perspective, and to attempt to put your technology advocacy on the same level as that will undoubtedly step on more than a few toes. Equating your set of practices or products to the Gospel seems like hubris to this group. Non-believers likewise see an “evangelist” as someone who, whether with the best of intentions or trying to pick their pockets, will tell them that they need to change their entire viewpoint and do things the way the evangelist believes.
As an “evangelist” in this sense, then, you want everyone around you to listen to you and accept your view. If you want to sell something, or accept a doctrine on faith, that may work in some cases. But if you want people to listen to you, you need to listen to them – and understand that you don’t always have all of the answers or even understand all of the issues.
One of the critical skills is the ability to change your position when presented with contradictory yet accurate evidence. Dogma is the antithesis of good analysis. Unfortunately I’d say over 90% of analysts take religious positions, and spend more time trying to make the world fit into their intellectual models than fixing their models to fit the world. When you are in a profession where you’re graded on “thought leadership”, it’s all too easy to interpret that as “say something controversial to get attention and plant a flag”.
Don’t try to make the tech world fit your model, because it won’t. Listen to others, and understand that sometimes you’ll need to change your viewpoint because you won’t always be right. Whether or not you believe that faith and dogma have a place in life, this isn’t it.