“There really is no place for Christ in many people’s Christianity. Their faith is not actually in Christ; it is in Christianity and their ability to live it out. This kind of ‘Christianity’ is really about shadow glories of human knowledge and performance. It does not require the death to self that must always happen if love for Christ is going to reign in our hearts.”
– Paul David Tripp, A Quest for More (Greensboro, NC; New Growth Press, 2007), 106.
(HT: Of First Importance)
Already Not Yet 
I wish I had the quote handy, but Heiromonk Fr. Seraphim Rose once said that Humanism is what is left of Christianty when Christ is removed from it, and that it is dangerous because it appeals to Christians and athiests alike.
One the one hand by removing Christ out of the picture it makes the religion ‘easier.’ It removes all the ‘troubleing’ things such as virgin births, hypostasis’, ressurection, etc. Christians are often mucn more comfortable with the ‘do good to others’ parts. On the other hand, athiests can see it as a way of reaching some kind of human plateau, where we can stop fighting about ideologies and instead again focus just on creating a ‘paradise on earth.’
Both lines of thought are extremely dangerous!