Antichrist can mean not only “against” and “opposite of”, but also “in place of." The basic belief of the above denominations may be valid, but what has been added to the basic simplicity of the Gospel of Christ? Whatever is added, complicates and takes away. If the Lord had thought we needed something in addition, He would have provided it. But He gave us exactly what we need. We have God's Word. We have the Holy Spirit and we have the fellowship of fellow believers.
Romans 1:16
For I am not ashamed of the gospel, for it is the power of God unto salvation to everyone who believes, to the Jew first and also to the Greek.