Because what can be known about God is plain to them – for God has shown it to them. His invisible attributes – His eternal power and His divine nature – have been clearly seen ever since the creation of the world, being understood through the things that have been made. So people are without excuse – (TLV) Romans 1:19-20
Nosh: Claiming or asserting that anyone is ignorant of God and therefore excused from the standard of redemption He requires is false. It is clearly stated here that there is more than enough evidence of His existence in creation alone to lead one to the knowledge of God. God personally guarantees that there is no reconciliation from Him apart from this and no exception to this truth.