1. It's a man made denomination.
2. They believe in the traditional trinity.
Although, there is one thing I agree with. The idea that we have an inner something, which they call an inner light, I call an inner voice. Whatever the case maybe. Man has a spirit. And when one becomes a Christian, it is his inner spirit that is regenerated, not the flesh.
From what I can gather in my brief research, Quakers believe that inner light is always there. While it is true, man has an inner spirit, it is not the Holy Spirit. The Holy Spirit enters when one is converted. Even a conscience must be developed, which depends on who we live with. We learn first from the family we are born into, or adopted by, etc. It is there we learn right from wrong, hopefully. And that is how our conscience is formed. So, I don't believe we have the little bit of God, or the seed of Christ, in us from birth.
Now, my mother was a religious person. She often played religious programs on the radio. And perhaps that is how I developed as I did. At a very young age that was all I was interested in. Then on my 7th birthday, my parents gave me a Bible. And I have loved that book ever since. Perhaps, that seed of Christ, or that inner light began developing back then.
In some children it never develops. Infants today are not too often exposed to religious programming on the radio. Or a mother singing hymns while she did her chores. That just doesn't happen too often. And it shows in society. Children are often messed up almost as soon as they are born.
Sorry, I am rambling, which I could do all day.