Why do some believers claim that all religions are just as good?

[AFTT47]

So if I'm understanding you right, there is nobody who loves God enough to get with his program - or if they do, they lack the will to do what is necessary?

[Drich]

Religions have very different concepts. There are theistic (most religions) and atheistic religions. The theistic ones can be politheistic or monotheistic. Their gods are vastly different. They have different explanations on how the world was created or works, they can't all be true.
Religions also have different concepts about afterlife. Christianity has Heaven and Hell, Hinduism and Buddhisn have reincarnation, Judaism is vague about this topic, some religions claim there is no afterlife and there many other examples. Sometimes, there are different beliefs about afterlife within the same religion, for instance, Catholicism has the concept purgatory, which is absent in other christian sects.
Dogma differs from religion to religion. There are different rules about treating others, what to wear, what to eat or drink, how to care for your health and many more.
I was thinking, are some of the people who claim that all religions are just as good actually lying, because they think they will come across as arrogant if they claim their religion is the true one?

I see that claim mainly by people who do not understand the religions they are talking about.

Now that said I say all Jesus Christ centered Religions are equal. Why?

We Christ at the center the religion then becomes about freedom, freedom to worship as strictly or as gracious as you like. How does that work? At the center of all Christ based religions is a foundation of forgiveness of sin. This means God forgiven when we willfully sin, it also means God all the more forgives when we try our hardest to understand but fall short. Meaning for example the bible does not say specifically when to pass around communion. Some churches do this every day, orther say once per meal other still say once a year on the feast of pentecost as the original was performed some one a month or once a week. In truth  Jesus simply said do this as a reminder of Him.. He did not give an appointed time. so then it becomes a matter of conviction as to the need you have in your heart. and that becomes your new measure.

[Succubus]

I agree, but there is another thing. Some christians I know claim that all religions are just as good...

If this is indeed the case then we can draw a parallel with other woo beliefs.
New-Age forums are easy enough to find but what isn't so easy to find is a Reiki healer calling out a homoeopath, a crystal healing practitioner, an ear candler or any combinations thereof. They dare not, cannot do that because then they will be asked by the likes of us to turn that same critical eye on their own beliefs. In the face of criticism; together we stand.

Remember when the ayatollah issued a death sentence on Salman Rushdie.
The response from the various bishops and archbishops was not: 'These disgusting bastards can go and fuck themselves'. No, the response was pretty universal among the priesthood: 'He shouldn't have blasphemed'. Together they stand.