Read Psalms 107:1&2  We are reminded in verse 1 that we should thank the Lord because He is good and his mercy endures forever.  Forever is a long time!  Think of the biggest number that you can.  God's mercy will last longer than that many years!  Then verse 2 says that if God has redeemed us, we should praise Him.  Redeemed means to buy back.  There are stores called pawn shops.  If someone is short on money, they take something of value to the pawn shop and the people will give them a loan for that thing.  They have to pay the money back and some extra money, and then they can get their thing back that they pawned.  They have to redeem that thing.  God made us and He owned us.  But we rebelled against God and became the slaves Satan and sin.  God redeemed us, He bought us back from Satan, our enemy, and now we belong to God.  I would rather be a follower of God than the slave of Satan.