Our Scripture reading today is 2 Samuel 24:22-25.
Verse 24, "And the king said unto Araunah, Nay; but I will surely buy it of thee at a price: neither will I offer burnt offerings unto the LORD my God of that which doth cost me nothing. So David bought the threshingfloor and the oxen for fifty shekels of silver."
We are able to be called the sons of God because of the great sacrifice of God's Son on the cross.  The penalty for our sin was paid in full by the sinless sacrifice of the Lord Jesus Christ.  He willingly gave His life that all mankind would have the opportunity to spend eternity in Heaven.  The more that we consider His sacrifice, the more we should be willing to sacrifice for Him.  King David knew it did not mean the same to offer His God something that did not have a price tag with it.  It should be our heart's desire to be completely sold out for God.  While we cannot earn His favour, we can seek to live holy lives for His honour and glory.  While we cannot earn eternal life, we can seek to live simply so that others can simply live.  The new birth costs us absolutely nothing, but the crucified life will cost us something.  We should not look at it as a negative, it is an honour to offer what life we have back to the One Who gave us and continues to give us everything.
Thank you, Jesus, for Your sacrifice!