Summary: A Casual Christian can be described as lukewarm. Casual Christians present a mixed worship, live a mixed lifestyle, and send a mixed message.
Introduction: George Barna has written a book entitled “The Seven Faith Tribes: Who They Are, What They Believe, and Why They Matter.” In that book Barna describes the seven tribes as Casual Christians, Captive Christians, Mormons, Jews, Pantheists, Muslims and Skeptics. He states that 66% of Americans are Casual Christians, which he describes as spiritually middle-of-the-road and at times ambivalent about their faith. He states that Casual Christianity is faith in moderation allowing one to feel religious without having to prioritize one’s faith.* Casual Christianity is often apathetic, lacking emotion, impassionate and indifferent. A Casual Christian can be described as lukewarm. Casual Christians present a mixed worship, live a mixed lifestyle, and send a mixed message.
I. Casual Christians offer a Mixed Worship
A. In the Old Testament, there are two primary words translated as worship. One is sach’ah, and it means "to bow down, or to prostrate oneself out of respect." It is a very clear, simple, concrete term. The second one is ash’ab, and it simply means "to serve," as a servant would serve his master. The most common Greek word for worship, found 60 times just in the New Testament, is proskuneo. It is another of those concrete terms. Literally it means "to kiss toward." It is almost like blowing a kiss at someone. Of course, this originated in bowing down and kissing the earth in front of someone or something that one might worship. It is equivalent to the Hebrew term sach’ah. Worship is therefore an inner reverence for God demonstrated outwardly in obedience, adoration and praise.
E. Casual worship often is either irreverent or indifferent, at times both:
1. Irreverent worship
a. Ezekiel 22:26 (quickview)  “Her priests have violated My law and profaned My holy things; they have not distinguished between the holy and unholy, nor have they made known the difference between the unclean and the clean; and they have hidden their eyes from My Sabbaths, so that I am profaned among them.
b. Irreverent worship is worship that is focused on satisfying the individual, the congregation or the community rather than the exaltation of an infinitely holy, righteous, and omnipotent God. It is focused on man and not on God. If worship is all about meeting my needs, my experiences, my feelings – me – then it is not the worship of God.
c. Deuteronomy 12:30-31 (quickview)  (NLT) “…be careful not to be ensnared by inquiring about their gods, saying, ‘How do these nations serve their gods? We will do the same.’ You must not worship the Lord your God in their way, because in worshiping their gods, they do all kinds of detestable things the Lord hates...”