Anyone can thank God regardless of how they understand Him. There are certainly greater steps to be taken in knowing Him personally but anyone can and should thank Him.
In this letter Paul spells out things about God for mature believers (Romans 15:14 – “I am satisfied … that you are… filled with all knowledge and able to instruct one another.“).
Paul states that God has revealed Himself to all people. He says that God has shown His invisible attributes, His eternal power and divine nature, clearly to all people through nature.
“For his invisible attributes, namely, his eternal power and divine nature, have been clearly perceived, ever since the creation of the world, in the things that have been made. So [people] are without excuse.”
Romans 1:20, ESV
At this point Paul’s is referring to everyone, saying that they have witnessed the demonstration of God’s invisible attributes which are clearly recognized through nature, ever since the creation of the world.
He then states that people know God exists and yet choose to do two things:
- Refuse to honor Him as God
- Refuse to thank Him as God
Here’s the statement spelled out
“For although they knew God, they did not honor him as God or give thanks to him ….”
Romans 1:21, ESV
Based on the second item, we learn that all people, regardless of their spiritual condition or special knowledge of God can thank Him.
The Bible teaches that everyone knows God exists and anyone can choose to thank Him.