How do you unlock the church in Resident Evil 4?

You have to go past the church first, and do a bunch of things; first you need to survive a swamp-like area full of ganados, after that, you have to fight a giant tadpole that the game calls "Del Lago." After that, you go to a waterfall area, and from there you are automatically led back to the save point with the merchant, where you proceed to fight "El Gigante." On your way back you automatically get the emblem thing that will unlock the church door. General tips; 1) If its a first run, acquire ALL the weapon types. You need to be armed to the teeth for most of the game until you get to Krauser, but we'll deal with that later. In your weapons inventory, emphasize the handgun, the shotgun, and the sniper rifle, in that order. These are the weapons you need to have; a sniper rifle, preferably the smaller one, a shotgun, the smallest possible, the little machine gun, the red 9 if available although you do not get it until you get to the castle, finally, the mine thrower which will be your best friend for most of the game. If you got the brain to know how to use it, the mine thrower is by far your best friend in this game. Forget incendiary grenades; they're worthless. You want to prioritize regular grenades and flash bangers. 2) Your upgrade priorities are; firepower, capacity, and reload speed, in that order. Priority guns regarding that upgrade priority are; the hand gun, hopefully a Red 9, the shotgun, and the sniper rifle. The machine gun and mine thrower can wait. Also, against Salazar's right hand otherwise known as "Verdugo," and against "It," you will need a rocket launcher. You use the rocket attack on Verdugo when he's frozen, even on pro mode it will kill him instantly. You use the rocket attack on "it," during the VERY LAST stage of the fight, when you're in the are with the explosive drums. DO NOT use the rocket launcher in the collapsible chambers; he's basically invincible there. 3) Find a corner, and shoot from there; tight corners cut off 5 directions from which ganados can surround you. Remember, this is not a "duck and cover" game, the enemy just keeps coming at you no matter where you are, thus, it makes sense to just go to a corner to keep from being surrounded, and pick them off from there. If you have really fast aim and slick gunplay skills, you can run around some. 4) When you get to Krauser, go ahead and sell the machine gun, sniper rifle, and mine thrower to fully upgrade the broken butterfly (the magnum). Krauser is almost impossible to beat without a fully upgraded Magnum, other guns just don't have enough firepower, especially on pro mode, and he's way too fast for a rocket launcher. You can always re-purchase the sniper later, as for the area after Krauser, sorry, you'll just have to aim really well. By then the Red 9 should be a more than adequate gun anyway. 5) The moment you see the merchant again, repurchase the sniper rifle; you'll need it against the regenerators. Speaking of the regenerators; at first, you'll need the magnum, but, in the freezer area, LOOK FOR THE INFRARED SCOPE, IT HELPS YOU SAVE AMMO. Also, the key to taking out the parasites on the Regenerator's back, is to shoot out one of its legs; that will cause the Regenerator to fall on its face, at which point you'll be able to shoot the plagas on its back. 6) Before challenging professional mode, get 5 stars with every character in mercenaries mode. 7) Beat Assigment Ada, as well as Separate Ways before taking on mercs mode. Far as defeating each boss, they're all generally pretty predictable; the toughest ones, are Verdugo, and "It." Without the rocket launcher, those two are ridiculously hard to kill, and if you are an RE4 virgin, both those bosses will put the terror of God into you; by far the scariest momments in the game, fighting those bosses. Remember; Verdugo ("salazar's right hand 'man'"), and "It," the rocket launcher is the only way to kill them, so spend your pesetas WISELY, focusing on upgrading only the handgun, shotgun, and sniper. good luck.