We drove up and down Rama IV Rd looking for the Hope of Bangkok, but we couldn't find it. I didn't know anything about the way that the street addresses work in Bangkok. Although I had the street number and the street name, the vital piece of information I had missed when the Singapore office gave me the address over the phone was the "Soi". You see in Bangkok an address might have a number on a main road, but actually be on side street know as a "Soi".
After a couple of times up and down Rama IV Rd, I asked the Taxi driver to phone the church and he got the answering machine and told me the message said that they were closed on Saturdays...