Civilization – Strategy to win “into the renaissance” scenario

I don't have a ton of experience with this scenario, but from what I've experienced so far, the key is the city states.

I played as France, which gives you a bunch of culture at the beginning of the game. I used this to push the Liberty tree immediately, getting a third settler and extra/faster workers. Since each settler turns into a size 3 city, its important to grow early on, and there are plenty of luxury resources to keep happiness from being an issue. The game may play quite differently for powers in different parts of the world, so consider this guide to be primarily for western Catholic powers.

Once I had my starting cities down, I focused on city state relations. Obviously this means that you need to make exploring an early priority, so that you can meet as many city states as possible. Once you meet a city state, you should start getting rapid fire quests from them. These quests often overlap, so you can gain relationship with several of them at once. Keep enough of an army so that you can take out barbarian camps as needed. By the time the first vote occurred, I received 9 votes, and I only had to use money to boost relationships twice.

In terms of faith, I started out by focusing on cathedrals to boost my faith (and culture) output. You don't really need the units early on, and you should be able to start accumulating faith quite quickly by befriending some religious city states. Once you have the faith rolling in from all your friends, you can use it to build up an army that should keep any aggressive neighbors at bay.

Not only does helping the city states give you tons of bonuses at a relatively low cost, but if you can secure Vatican City, you should rack up the victory points without much issue, between the Roman Catholic Emperor vote and the bonus points for being allied with a holy city. I ignored Jerusalem, since it was quickly conquered by the Turks anyway.