Micah 6:6-8
6 With what shall I come before the Lord, and bow myself before the High God? Shall I come before Him with burnt offerings, with calves a year old? 7 Will the Lord be pleased with thousands of rams, ten thousand rivers of oil? Shall I give my firstborn for my transgression, the fruit of my body for the sin of my soul? 8 He has shown you, O man, what is good; and what does the Lord require of you but to do justly, to love mercy, and to walk humbly with your God?
6 With what shall I come before the Lord, and bow myself before the High God? Shall I come before Him with burnt offerings, with calves a year old? 7 Will the Lord be pleased with thousands of rams, ten thousand rivers of oil? Shall I give my firstborn for my transgression, the fruit of my body for the sin of my soul? 8 He has shown you, O man, what is good; and what does the Lord require of you but to do justly, to love mercy, and to walk humbly with your God?
Does God demand sacrifices to please Him, even to our firstborn? No. All the deeds we do fall short of pleasing Him - what He really desires is our heart of obedient, humble, merciful, devoted love for Him. This is why Jesus said the greatest commandment is to love God with all we have and are, and then to love others as we love and care for ourselves. The biggest sacrifice is praise to Him in these things, for all comes from and goes to Him.