Actually, it is the other way around. You need to start using the whole Bible instead of only the parts that make you happy. You can't pick and choose.

If you don't use the Bible, but you do listen to the Pope, how do you know if your faith lies in truth? Maybe you are having faith in falsehood.

For example. There is no place in the Bible that suggests that you can pay your way into Heaven with money. But there are Popes in history that have said that you can do this. I don't follow what the papacy says right now, but this might even be a teaching that is being taught by Rome right now. It is completely against Bible teaching.