Amos 5: 4, 6, 8 and 14

"For thus says the Lord to the house of Israel: "Seek Me and live;"; "Seek the Lord and live, Lest He break out like fire in the house of Joseph, and devour it, with no one to quench it in Bethel"; He made the Pleiades and Orion; He turns the shadow of death into morning and makes the day dark as night; He calls for the waters of the sea and pours them out on the face of the earth; the Lord is His name."; Seek good and not evil, that you may live; so the Lord God of hosts will be with you, as you have spoken."  Amos 5: 4, 6, 8 and 14.

We are clearly commanded to seek God.  "Seek," in this case, does not mean to search for something that is lost.  We have already been invited into a relationship; we already know where God is.  We do not have to search God out as if He is lost somewhere.  Seek means, as the Expositor's Dictionary says, "to turn to Him in trust and confidence."

Barnes Notes comments: "It does not mean to seek to get something from Him, but rather to seek God for what He is in Himself."  This hits the nail right on the head, because, "what He is in Himself" is another way of describing "seeking to be in the image of God."  Do this, and we will live forever, as He does.

When He says "live," He means "live abundantly" and "everlastingly."  Regardless of how much we have in the way of material goods, we can still live abundantly, but this is directly tied to "seeking" Him.  We seek Him to be like Him.  We seek Him to build the relationship with Him.

The commentaries note that both "seek" and "live" are in the imperative.  It is a command to be diligent, fervent, and persevering in following through in"seeking."