2 Samuel 24:24 "...I will not offer burnt offerings to the Lord my God which cost me nothing..." (NASB)
Whatever we offer to God has to cost us something, or it isn't a sacrifice. If it isn't a sacrifice, then what is it? What purpose does it serve? God doesn't need our self-righteousness. He doesn't need us to give Him something only to be seen doing it. He wants our honesty in our giving. By giving God our sacrificial offering, we are affirming our faith in His ability to meet our needs. We are saying, "I trust You, Lord."
Abraham's sacrifice was to be his promise (his son), but Jehovah Jireh provided a ram at just the perfect moment. God is still the same; we can trust Him just as Abraham did. We can give Him our very lives as a living sacrifice. What good is an offering that costs us nothing? Sure, it can still be used for the kingdom, but how is it benefitting our spiritual lives? When we give out of our abundance it's nice, but when we give out of our scarcity.... That's the sacrifice. That costs us dearly, and that is worthy of offering to the Lord.
I trust You, and I need You to know that You can trust me with what You have blessed me with, Lord. Here is my SACRIFICE.