- Nicky is thinking of giving up her job. — OK.
- Do you believe in God?
- I feel hungry. Is there anything to eat?
- This sauce is great. It’s tasting really good. — OK.
- I think this is your key. Am I right?
Глаголы believe, feel и think в данных значениях обычно употребляются в Present Simple. Think of в значении «обдумывать» и taste при описании вкуса могут употребляться в форме Continuous.