Amos 4:4-5 (ESV)
“Come to Bethel, and transgress;
to Gilgal, and multiply transgression;
bring your sacrifices every morning,
your tithes every three days;
 offer a sacrifice of thanksgiving of that which is leavened,
and proclaim freewill offerings, publish them;
for so you love to do, O people of Israel!”
God is not giving commandments here to do the things listed. We know that because the things listed are sinful. He is mocking the people for their hypocritical worship, their self righteousness. Verse 5 God says that the people offer sacrifice of thanksgiving of that which is leavened. That is, the people come to offer a thank offering to God for blessings He has bestowed and they break the Law in doing so.
They decide how they are going to approach God. Leaven was forbidden in the offering because leaven is a symbol of sin. They come without repentance to thank God. They want to worship but they are not willing to come the way that God says they should. They are not willing to turn from sin. They bring their sin with them into the presence of God. This is no small matter.
The trouble with many Christians however, is that even while they read this and agree that what was going on in Amos’ day was horrible, they do not see that they are doing the very same thing. Until the leaven is removed we cannot worship. This means, first of all, that outside of Jesus Christ it is impossible to worship God at all. He and He alone is able to remove the leaven. We must trust Him to remove our sin and guilt. He is the only way to God and as worship is coming into the presence of God then we must have our sin dealt with first. All our sin. This is the miracle of grace. Despite our sin, because we are in Christ we can worship. We come into the presence of God and are welcomed. Not because we are righteous, but because we are in Christ and He is righteous.
Secondly, even true believers are able to commit the sin of bringing leaven into the worship. We come to God with gossip still fresh. We approach God with unrepentant hearts. We come with an attitude of superiority over those who do not believe. There are other believers we will not talk to while we expect God to talk to us. We come into the place of worship thinking we know the Bible better than others. We see someone who will not sing and we think we know why – because they are lacking spirituality. We come to critique the sermon, the singing, the hearts of others who come in, the preaching. We come with bitterness against God. We come hoping to be entertained. We give very little money, time, prayer and effort into cultivating true spirituality. We have little or no concern for the lost, the welfare of others, the heart aches of those who worship with us. We hate Muslims, Hindus, evolutionists and atheists. We come with a Bible that has hardly been open since the last time we worshipped and our knees are in no danger of being calloused from prayer. We think we know the solution to the church’s woes and we know that the reason the woes continue is that no one listens to me.
Leaven. There is no shortage of leaven. To bring our leaven into the place of worship and expect God to accept the worship is no small wickedness. It needs to be excised and it needs to be done now.
The miracle of saving grace should always bring a sensitive heart that works, by the power of the Holy Spirit, to put sin to death. To be willing to enter into worship unconcerned about our sin is a sign that we may not be in Christ at all.