Today, Secular Humanism is not considered a religion. However, based on the dictionary definition and much additional evidence we can show that not only is it a religion, but one that is in diametric opposition to biblical Christianity. The Merriam-Webster dictionary has basically five definitions for “religion.” They are:

1. The service and worship of God or the supernatural
2. A commitment or devotion to religious faith or observance
3. A personal set or institutionalized system of religious attitudes, beliefs, and practices
4. Scrupulous conformity
5. A cause, principle, or system of beliefs held to with ardor and faith

Only the first one is specific about service and worship to a God or the supernatural. The other four basically relate to the secular realm. Let’s call these later beliefs “religious secular” beliefs. 
This may sounds like an oxymoron, but that is only because we have been programmed to relate only religious beliefs to that of the supernatural.

By denying the last four definitions of religious or religions above, the religious secular realm can exempt themselves from all the restrictions and condemnation they place on religions that worship a supernatural God. This deception, along with “Case Law” replacing “Constitutional Law” has provided a basis for the whole false “separation of church and state” doctrine. The original source of the “Wall of Separation” metaphor was from a letter from Thomas Jefferson written to the Danbury Baptist Church. The context was an assurance that Jefferson would keep the state out of the church. It had nothing to do with keeping the church out of the state or government! The context of the establishment clause of the Constitution was to prevent us from declaring a state sanctioned Christian religious denomination not preventing us from being a Christian nation!

In addition to the dictionary supporting the fact that Secular Humanism is a religion, secular Humanists themselves claimed that they were a religion for more than 100 years and the Supreme Court confirmed it. Wikipedia documented the following under “Torcaso v. Watkins Case Law:”

The phrase “Secular Humanism” became prominent after it was used in the United States Supreme Court case Torcaso v. Watkins. In the 1961 decision, Justice Hugo Black commented in a footnote, “Among religions in this country which do not teach what would generally be considered a belief in the existence of God are Buddhism, Taoism, Ethical Culture, Secular Humanism, and others.

The following two quotes provide additional evidence that Secular Humanism is a religion.

Secular humanist John Dewey described Humanism as our “common faith.” Julian Huxley called it “Religion without Revelation.” Many other humanists could be cited who have acknowledged that humanism is a religion. In fact, claiming that humanism was “the new religion” was trendy for at least 100 years.

John Dunphy, a secular humanist, wrote in the Humanist magazine,

I am convinced that the battlefield for humankind’s future must be waged and won in the public school classroom.  The classroom must and will become an arena of conflict between the old and the new – the rotting corpse of Christianity, together with all its evils and misery, and the new faith of humanism.  .  .

This certainly shows that humanists and their beliefs are parallel and opposite of Christian theism. So consequently, what has happened in our schools and in our culture under the guise of replacing religion with secularism is that we have replaced a true religion with a false religion.