Sassetta,
St. Francis Kneeling before Christ on the Cross,
c. 1437-1444
So, time immemorial would equal eternity or God. And a progression of thoughts would equal our existence. We exist for God to allow us to travel freely through time and then to evaluate the experience. You can also evaluate the past to reach the present or the future. There are some of us who think beyond grace or the gracing of God with an activity and then there are those who do not possess the knowledge nor acquire it through learning or are even able to process the thinking of anything complex. We are all here for a purpose, even though this is often shrouded in mystery and can take you your whole lifetime to understand what the purpose is. Time is often equated differently with different individuals. When there is a progression of thinking, time exists and when we regress to another state or even stay the same, time appears to stand still. The journey it takes to transgress to the thinking necessary to progress is not something that is easily obtained and requires a vigorous amount of time and mental strength.
Sassetta (detail)