At what point do our sacrifices become unacceptable? Does God have a standard for how we are to approach Him, or can we simply come however we see fit? It is becoming more and more common to hear that we can come as we please and so long as we are sincere God will accept it. We can take the physical side of yoga and remove it from the intertwined spiritual aspects without concern. We can take things that originally were found in other religions and slap the name of Jesus on it and that will make it "Christian." Or will it? And can we really do a service in the name of God and demand reward for it? If I do x, y, and z do I force God's hand into giving me what I want? If I do 10 prayers does that mean I will get what I want? And if I'm willing to do 100 prayers will I get 10 times as many blessings? Is God a genie that is willing to give whatever we want so long as we bring something, anything to Him? If we just rub that little bottle He'll answer our prayers, after all He has to. Doesn't He?
To what purpose cometh there to me incense from Sheba, and the sweet cane from a far country? your burnt offerings are not acceptable, nor your sacrifices sweet unto me. (Jeremiah 6:20)
It seems to me that we can't just do whatever we want and expect God to accept it. If we can pick and choose our methods for approaching God from other religions, why then shouldn't we just be able to follow those other religions and still come to God? If God is going to accept certain aspects of false religions as a way to come to Him, why then would He insist that coming to Him through Christ's sacrifice is the only way (John 14:6)?
If we could make sacrifices to God in whatever manner we wanted, why would He kill Aaron's sons in Leviticus for doing this very thing?
And Nadab and Abihu, the sons of Aaron, took either of them his censer, and put fire therein, and put incense thereon, and offered strange fire before the LORD, which he commanded them not. And there went out fire from the LORD, and devoured them, and they died before the LORD. Then Moses said unto Aaron, This is it that the LORD spake, saying, I will be sanctified in them that come nigh me, and before all the people I will be glorified. And Aaron held his peace. And Moses called Mishael and Elzaphan, the sons of Uzziel the uncle of Aaron, and said unto them, Come near, carry your brethren from before the sanctuary out of the camp. So they went near, and carried them in their coats out of the camp; as Moses had said. And Moses said unto Aaron, and unto Eleazar and unto Ithamar, his sons, Uncover not your heads, neither rend your clothes; lest ye die, and lest wrath come upon all the people: but let your brethren, the whole house of Israel, bewail the burning which the LORD hath kindled. And ye shall not go out from the door of the tabernacle of the congregation, lest ye die: for the anointing oil of the LORD is upon you. And they did according to the word of Moses. And the LORD spake unto Aaron, saying, Do not drink wine nor strong drink, thou, nor thy sons with thee, when ye go into the tabernacle of the congregation, lest ye die: it shall be a statute for ever throughout your generations: And that ye may put difference between holy and unholy, and between unclean and clean; And that ye may teach the children of Israel all the statutes which the LORD hath spoken unto them by the hand of Moses. (Leviticus 10:1-11)
If God is a God of order, and we know He is, then why would He be so disorderly that man could choose to do whatever he wanted? This idea contradicts all of Scripture. He set up the world in a specific order, the way the ark was to be built, He had Abraham come to a specific mountain to offer Isaac in sacrifice, He brought the Israelites out of Egypt along a specific path, specific ways for how the tabernacle was to be laid out, even the way the land was divided once they were able to enter the land was very specific and left no doubt as to who lived where. God was so specific that He gave over a hundred prophecies concerning the coming of His Son. So, if God is going to be that detail oriented in everything else, why do we seem to think that He doesn't have specific things He will and will not allow as valid ways of worshiping Him?
Many will say to me in that day, Lord, Lord, have we not prophesied in thy name? and in thy name have cast out devils? and in thy name done many wonderful works? And then will I profess unto them, I never knew you: depart from me, ye that work iniquity.
Likewise just doing the "right" thing isn't good enough. Our hearts must be engaged, we must serve because we long to see God glorified, not to attempt to use our servanthood as something to dangle over God's head. He wants us to do what He commands because we love Him, to desire His glorification over all else. God doesn't do half way. Christ said that those who love anyone more than Him are not worthy of Him (Matthew 10:37), He shot down the Pharisees outward righteousness because they were not doing their works out of a pure heart (Matthew 23:25). Clearly doing "good" to appear righteous is not righteous at all, one must do good because God has commanded us to do so and one must do that work faithfully with a clean heart to the glory of God.
And whatsoever ye do, do it heartily, as to the Lord, and not unto men; (Colossians 3:23)