"Mercy, peace and love be yours in abundance." NIV translation
Jude explained who we are in the previous verse and now he tells us of the abundant blessing that is in that relationship. First, is mercy and the fact that God, who is fair in handing out justice, does not have to punish us for our sins as the punishment was taken by Jesus Christ. Though we may stumble and disobey God each and every day, those sins are already paid for as well. His name is El Elyon (Most High God) the One with supreme authority because He created all things and since He says our sins are paid for, it is settled.
The second, is peace and the fact that, since our sin (disobedience) was punished, we are no longer His enemies but we are now His children.
His name is El Tsaddik (just and right) and we are now in agreement with Him and so we are also right.
The third, is love and, since we are His children and He is the ultimate Father, He watches over us and cares for each of us in a way that no earthly parent has the power to do. His name is El Hanne'eman (faithful) and He will support and nourish us and never forsake or forget us. His name is also El Shaddai; the One who has the ability to supply what we need.
"Dear friends, although I was very eager to write to you about the salvation we share, I felt I had to write and urge you to contend for the faith that was once for all entrusted to the saints." NIV translation
Now, Jude gets to the purpose of his letter as he addresses it to "Dear friends". He is actually talking to the beloved which refers to how we are connected to each other through our connection to God in love. He goes on to explain that he wanted to bring an encouraging word about salvation but instead was instructed by the Spirit to send another message. The message that he is going to share is about contending for the faith. This word contend actually is more intense than it may seem as it describes agony faced in the struggle. He then reminds them (and us) that the good news of Jesus Christ has been entrusted to us to proclaim clearly and accurately so that people will not be deceived.
"For certain men whose condemnation was written about long ago have secretly slipped in among you. They are godless men, who change the grace of our God into a license for immorality and deny Jesus Christ our only Sovereign and Lord." NIV translation
Now, we are introduced to the problem and it seems that it is so very widespread today. The problem is that some have "secretly slipped in among you". There are many that are counted among God's people but are in fact condemned as Jude says here. God knew about these people even before they existed and we were warned by the prophets of the past as well as the apostles. These people have claimed the grace of God through Jesus Christ and his forgiveness but they do not even try to stop sinning. They arrogantly continue in their sin and even go so far as to approve of sin because of grace. As Jude says, they have turned it into a "license for immorality".