I believe the verse you are referring to is Ecclesiastes 3:11 which says, “He has made everything beautiful in its time. Also He has put eternity in their hearts, except that no one can find out the work that God does from beginning to end.” (NKJV).

First, we learn that God’s works are all done well.  There is order, harmony, and beauty in all the Lord does, even when we do not understand His works or His ways.  Solomon had stated earlier in verses 1-8, “To every thing there is a season, and a time to every purpose under the heaven: A time to be born, and a time to die; a time to plant, and a time to pluck up that which is planted; A time to kill, and a time to heal; a time to break down, and a time to build up; A time to weep, and a time to laugh; a time to mourn, and a time to dance; A time to cast away stones, and a time to gather stones together; a time to embrace, and a time to refrain from embracing; A time to get, and a time to lose; a time to keep, and a time to cast away; A time to rend, and a time to sew; a time to keep silence, and a time to speak; A time to love, and a time to hate; a time of war, and a time of peace.”  It was said of the Lord Jesus in Mark 7:37, “He hath done all things well…”  The Lord is so precise in His actions.  If it is from His hand, it is good and beautiful. 

“He has put eternity in their hearts.”  The word ‘eternity’ is translated as ‘the world’ in the KJV.  However, the Hebrew world ‘o-lawm’ is properly translated as ‘eternity’.  In fact, it is translated in other places in the Old Testament as ‘for ever’ (Genesis 3:22), ‘everlasting’ (Genesis 9:16), ‘evermore’ (2 Samuel 22:41), and so on.  From this, we learn that we all have been given a sense of the eternal in our hearts.  There is a sense that we realize that there is more that just this life we live.  There is something beyond this…something eternal.  C.S. Lewis once said of this, “If we find ourselves with a desire that nothing in this world can satisfy, the most probable explanation is that we were made for another world.”  Of course, it is impossible to understand or conceive eternity apart from the knowledge of God.  Apart from Him, “no one can find out the work that God does from beginning to end.”

Solomon goes on to speak of God’s eternal purpose and plans in verse 14, “I know that, whatsoever God doeth, IT SHALL BE FOR EVER: nothing can be put to it, nor any thing taken from it: and God doeth it, that men should fear before him.”

It is undisputedly true that we are the only beings on this earth who can think the thoughts and speak knowingly of eternity. Other creatures have no ability to even think about eternal things.  As humans, we have the ability to consider eternity and to know God.  We have that truth brought out in Job 32:8, “But there is a spirit in man: and the inspiration of the Almighty giveth them understanding.” 

Throughout history, every civilization and culture has had some thought about eternity.  Even those who have never heard of the ONE TRUE GOD, seem to understand there is something going on beyond this life.  Also, every civilization and culture has some sense of good and evil and thoughts of being good enough to experience a blissful eternity. 

Is there a definite way to experience an eternity in perfect happiness and joy?  YES, THERE IS!  When we truly come to realize that we cannot overcome the guiltiness for our sins, we will humble ourselves and look outwardly for one to save us from our sins.  We read in Romans 5:8-9, “But God commendeth his love toward us, in that, while we were yet sinners, Christ died for us. Much more then, being now justified by his blood, we shall be saved from wrath through him.”  The wrath of God for our sins was spent on His precious Son, so that we, through faith in the Lord Jesus, might be forgiven of our sins and dwell in Heaven with Him for all eternity.  Unless we have allowed the world to take away our sense of eternity, we realize that we will all spend eternity somewhere.  May I ask, where will you spend eternity?  2 Thessalonians 1:9 tells us that those who reject the Lord Jesus Christ as their savior, “shall be punished with EVERLASTING DESTRUCTION from the presence of the Lord, and from the glory of his power.”  Those who put their faith in the Lord Jesus Christ will one day hear these words of the Lord, “…enter thou into the joy of thy lord.” (Matthew 25:23).  The Lord Jesus, speaking of those who believe on Him said in John 10:28, “And I give unto them ETERNAL LIFE; and they shall never perish, neither shall any man pluck them out of my hand.”  Dear friend, you will spend eternity somewhere…either in EVERLASTING DESTRUCTION or enjoying ETERNAL LIFE in the presence of the Lord.  I trust that if you have not, you will put your faith in the Lord Jesus Christ today.  Romans 10:9 assures us, “That if thou shalt confess with thy mouth the Lord Jesus, and shalt believe in thine heart that God hath raised him from the dead, thou shalt be saved.”  (444.2)