“Without cost you have received; without cost you are to give.” (Matthew 10:8)

While meditating this passage, it comes to my mind that Jesus has another saying:

“So should it be with you. When you have done all you have been commanded, say, ‘We are unprofitable servants; we have done what we were obliged to do.’” (Luke 17:10)

The driving force of “giving” comes from “love”. The foundation of “love” is the life of “Holy Trinity”.
Father, Son and Holy Spirit are a loving relationship. If the Father does not love the Son, then He is not the Father. If there is no mutual love between Father and Son, there is no Holy Spirit.

We, as humans have shared the part of God in nature. If we have received without cost and do not share with others, we will become a selfish person. If this is so then the Kingdom of Heaven will have no place for us.
  
In fact, God has given humans the greatest gift; that is the life of God’s creations. If we do not put the words of God into practice, we will have no place in the life of God.