You can't serve God if you aren't graduated from full-time training.

After the Lord's table or Sunday service meeting, I got a fellowship with LC members. They told me that I had to go to full-time training (I may choose between Full time training for young people or middle aged ). I was told that if I couldn't graduated from the training, I couldn't serve the Lord.

Personally, I probably want to go to training. But there are some regulations in there such as haircut or dress code which I can't fulfill the requirements. Personally, I like to shave my head (but I has nothing to do with nazi skinhead or racist movement) and I don't like to wear Shirt with necktie or pants (Some kind of business man style ). These two things are obstacles for me to go to training. So, I decided to not go but local church members told me that I can't serve Him if I am not graduated from full time training.

Is it my fault for not having something that is according to these regulations ? I'm in flesh or natural man. What's wrong with me to have my head shaved and wear the outfit that I like? In Christ, should we have no natural favorite lifestyle which is not related to immorality ? Please help me what should I do?

This is what Witness Lee lectures his followers concerning outward appearance which I have found in full-time training website :
“We also have the burden to help the trainees to grow absolutely in the divine life. Finally, they have to be built up in their character. They need to be trained to dress properly and to give people a good impression of their appearance. If we do not have a good appearance, who will listen to us or respect us? We must adjust ourselves. If a co-worker teaches the truth without a necktie, the people’s confidence in him will be killed. The way we dress, cut our hair, and comb our hair will give us a proper appearance which can help gain people’s regard and respect. In the past we were too loose and self-contented. Those who work for the Lord should dress in a way that is fitting in the Lord’s work.”
Witness Lee, Elders’ Training Book 9 – The Eldership and the God-Ordained Way (1), p. 15, ch. 11

But the Lord said :
But Jehovah said to Samuel, Do not regard his appearance and the height of his stature, because I have rejected him. For it is not how man sees that matters; for man looks on the outward appearance, but Jehovah looks on the heart.(1 Samuel 16:5)

I still believe in the word of God more than human teaching. What's about you brother and sister, what do you think about this matter ?