After the Joker!
As we grapnel and glide to the Church we will spot the crowd of thugs standing guard and patrolling outside -- drop down and take them out, then head along the street to the left of the Church to battle a small group of thugs and encounter a ringing telephone! When we answer the phone it is none other than Victor Zsasz on the line! Answering the phone unlocks the Achievement "Ring Ring" (5 GS) for answering a ringing phone.
Now that we have managed that, backtrack to the Church and take out the trio of thugs in front of the door -- now at this point you can either go into the Church or you can patrol the surrounding neighborhood for some more battles and thus bonus XP -- it is your call! I chose to grind out levels to gain some of the upgrades that are presently available and so began to patrol the area. I seriously suggest you do the same since having these upgrades really does make a difference!
Note that if you look around in Detective Mode you will see the Security Cameras highlighted in orange -- these can be taken out with a Batarang attack and will earn a small amount of XP for your efforts.
Cold Call Killer Side-Mission
--== Cold Call Killer Side-Mission ==--
In addition to the thugs there are Political Prisoners you can talk to and then you will get another ringing phone -- use Detective Mode to track it down to get the next link in the chain which is another ringing phone. There is a timer and you need to get to it before the timer runs out and answer it or you fail, and he kills someone!
There is a compass pointer to follow and of course once you are close use Detective Mode to spot the phone's location -- quickly answer it to get the next conversation and complete this part of the mission! To start the next part you need to find another phone, rinse and repeat, but for now let's kick some serious butt in this area as it is a target-rich environment!
Between completing the side-mission and two group battles you should quickly Level Up! Pick the upgrade that you want -- I went with Combat Armor v1.0 myself, and then went ahead and did a few more battles (watch out for the armed thugs mind you, you are not ready for them in groups yet) to Level Up again and chose the Ballistic Armor Upgrade v1.0 this time!
You can head for the Church any time you like -- but you really are better off roaming through the streets and doing battles, taking out cameras, and doing any convenient side-missions that you come across -- at least until you have maxed out the Armor upgrades and picked up the Combat upgrades as well. Yeah, it is something of a grind, but it really gives you a massive edge on the upcoming story line content!
Another side-mission you can get is rescuing Political Prisoners -- basically if you hear someone being interrogated as to the location of Bruce Wayne, that is the start for one of these missions -- just put the beat-down on the bad guys to rescue the guy and you score a tasty chunk of XP and can feel very good about yourself! The one closest to the Church is the reporter Jack Ryder, who once you save you should talk to as he will spill his guts and tell you all he knows about Dr. Strange.