In examining the central issue of the first few commandments, we find that the first concerns what we worship. These verses in Romans 1 recap what the first commandment forbids, the worship of someone or something other than the Creator. Worship is the devoted service that an individual gives to what he regards above all. It is most assuredly not restricted to activity done on only one day of the week. As verse 25 shows, a person can give devoted service to created things as well as to the Creator. In addition, Paul observes in Colossians 3:5 that covetousness is also idolatry, amplifying the fact that a person can give unlawful respect and thus devotion to things other than the Creator God.
We have all heard the argument that "all religions are good," but this is simply not true. Based on what it produces as a way of life in countries where it dominates, is militant Islam good? Are this world's many variations of what is called Christianity good? This world's religions can be evaluated as good or bad only in relation to each other. Not one of them is good when evaluated against Jesus' religion, the one He passed on to the apostles.
Paul's argument in Romans 1 is that God abandoned to uncleanness those addressed as idolaters. The term "uncleanness" indicates immorality and strongly implies sexual immorality. Based on these few verses, the conclusion is that any religion other than the true one is in reality a curse—actually, in some ways a punishment—even though it may occasionally produce some good effects!
The context pinpoints their sin in verse 25: "They exchanged the truth for the lie." Notice the definite articles. Here, God and His way is "the truth," and the people's idolatry is "the lie." How can that be good? Paul is showing that only the Creator God can be worshipped profitably. Worshipping someone or some thing other than the Creator subtly turns the thrust and direction of a person's life off the true path of God's purpose because the source of the authority permitting or guiding his conduct is not the true God. Even though the object of devotion may be otherwise harmless, it is sin to give it that level of respect because it absolutely cannot produce anything good toward God's purpose.
Recall that idolatry is a sin whose fruit is almost never immediately seen. It is like a cancer that destroys by slow increments. Life's direction and any course corrections must come from within one's relationship with the Creator God. The wrong source will lead one astray. Clearly, properly keeping the first commandment requires a great deal of soul-searching evaluation of the true value of what we hold dear.