"So the last shall be first, and the first last."
I have always struggled with this concept. I pictured a line of people waiting to get in, where the order of people is reversed so that the guy standing at the back moved to the front and the guy at the first of the line moved to the back, but it never sat well with me and I couldn't work it out. Silly girl, context is king. I should have looked at the parable Jesus had just told to get my answer, since verse 16 is the conclusion to that parable.
Today I read this note in my MacArthur Study Bible: "In other words, everyone finishes in a dead heat. No matter how long each of the workers worked, they each received a full day's wage. Similarly, the thief on the cross will enjoy the full blessings of heaven alongside those who have labored their whole lives for Christ. Such is the grace of God.
My mind's illustration of the verse has changed. Now I think of the guy at the front of the line standing side by side with the second guy, who is side by side with the third guy, and so on until the last guy in line is standing side by side with the guy in front of him. All are equal. All are first in line. A tie of all who are in the race. Everybody gets in first. Nobody comes in later. That is how God is with His children.
But if you don't know Him, you can't even stand in the line, let alone get into heaven...only Jesus can get you in.