How do we know that God's witness is evident in creation?

The sermon references Romans 1, which states that God's invisible attributes, namely His eternal power and divine nature, have been clearly perceived in the things that have been made. This means that creation itself acts as a testimony to God's existence and wisdom. Additionally, Psalm 19 affirms that the heavens declare the glory of God, and their voice goes out to the ends of the earth, meaning that all people have access to this general revelation. However, this revelation is insufficient for salvation, as it does not provide the necessary revelation of God's redemptive plan found in scripture. For true knowledge of God and salvation, one must turn to His written word.