Israel fell into idolatry through fornication. The physical fornication produced spiritual fornication, which is idolatry.
In Revelation 2:14, within the comments to the seven churches, we find this problem still haunting the church. It actually surfaces in Revelation 2:6, where it speaks of the deeds of the Nicolaitans, which God hates, but it is more clearly stated in verse 14 to the church in Pergamos.
But I have a few things against you, because you have there those who hold the doctrine of Balaam, who taught Balak to put a stumbling block before the children of Israel, to eat things sacrificed to idols, and to commit sexual immorality.
It is a problem in two of the first three churches, and it surfaces again in verse 20, this time in Thyatira.
Nevertheless I have a few things against you, because you allow that woman Jezebel, who calls herself a prophetess, to teach and seduce My servants to commit sexual immorality and eat things sacrificed to idols.
Today, we are bombarded on every side with sex. It is something that, even if one is blind, cannot be escaped because we hear about it. It is presented to us as an inducement to do something.
In Numbers 25, the inducement is to idolatry. Today, the inducement is to get us to buy, to get us in debt, to get us to be slaves of the lender. So sex is thrown at us in things in which it should not even appear—selling pipe wrenches or automobiles. It is used as an inducement, and we have to be very careful because it is so incessantly shoved in our faces.
John W. Ritenbaugh
Passover and I Corinthians 10