Romans 10:9

"If you confess with your mouth that Jesus is Lord and believe in your heart that God raised Him from the dead, you will be saved."

 
This is one of the most important verses in the entire Bible -- It tells us the requirements to be saved!
 

"This sounds like 'magic words'.  Do you mean to say that if I just say the words and believe Jesus came back from the dead I'll go to Heaven?  Even if I live a horrible life?"

NO!  It means you must follow Jesus' teachings and believe God raised Jesus from the dead. Like all other fields, the Bible has some special "technical jargon" -- words that are used in a special way.
 

In the Bible, to confess means to agree with the will and word of God, to agree that God is correct in what He says.

"If you confess with your mouth ..." means "If you openly say (and believe) that God is correct when He says ..."
 

Lord means that He is the leader and you are a follower.

"... Jesus is Lord ..." means you are openly stating that you intend to try to live the way Jesus said we should live.

Luke 6:46 Why do you call me, `Lord, Lord,' and do not do what I say?