“But do not overlook this one fact, beloved, that with the Lord one day is as a thousand years, and a thousand years as one day.” 2 Peter 3:8
Some use this verse to explain that the days in Genesis were long periods of time, not literal 24-hour days. This verse, however, is not at all talking about the length of time during the Creation week. It is in reference to Psalm 90:4 “For a thousand years in thy sight are but as yesterday when it is past, and as a watch in the night.” The context in this verse is that of Jesus’ followers asking Peter when Jesus would return. Scoffers at the time were mocking Christians because they were awaiting Jesus’ return, yet he had not returned. Peter explained to the followers that God is outside of time as we understand it. A day to God is like a thousand years, and a thousand years are like a day. In other words, the verse cancels itself out in regards to explaining and understanding time.
Imagine you watching a parade. You may be at the beginning, middle, end, or somewhere in between. You are in one place seeing only part of the parade. Imagine God in a helicopter above you, getting a bird’s eye view of the entire parade at one time. God is outside of time and space as we understand it.