How do you get pass the water house in Pokemon fire red?

In Pokemon FireRed, you can get past the water house by obtaining a Bike Voucher. You can find the Bike Voucher in Mt. Moon. It is located on the ground to the right of the large rock you need to push to progress through the cave. Once you have the Bike Voucher, take it to the Cycle Shop in Cerulean City and trade it for a bike. You can then use your bike to cross the water and continue your adventure.