"If I have seen further it is by standing on the shoulders of giants." Isaac Newton
Having a mentor will be one of your keys to being a successful teacher. The most successful people I know, had a mentor cheering them on each step of the way. Their mentor saw in them what they did not necessarily see in themselves, and their mentor was there to brush off their knees after a fail.
The ideal mentor is one with whom we can share our career goals with. A person who has walked in our shoes and been successful. They understand the challenges that lie ahead, and genuinely want us to overcome each one. Ideally, it is nice to be able to talk with that person on a consistent basis.
If you don't have someone you consider a mentor I would suggest looking for one. Seek out the teacher whose character and teaching style you would like to reflect, and they don't have to be a Bible teacher. Request to sit in on their classes, or go in after school to ask questions.
If your school does not have a mentor program, suggest the idea to your principle. A mentor program is used in many schools, and new teachers, the students, and the school will benefit from providing this support to their employees.
Also, it's okay to have more than one mentor. I have heard many Pastors reference their mentors who are long dead. Nothing can replace a living, in the room mentor, but we can learn much from those who are gone, or alive but far away. If you want to improve your presentation skills, study those who are amazing presenters. Watch what they do and learn from them. If you want to have better relationships with your students, find those people who have a knack for connecting well with others and learn from them. Don't put yourself in a box, and believe you can get better.
I strongly believe many teachers are too isolated. Too often we rely on our own finite wisdom, and waste time by reinventing the wheel. It does take a level of humility to realize you would benefit from a mentor. Being vulnerable and admitting to a co-worker you're not a perfect teacher, you have weaknesses you would like strengthened, is not easy. However, in that vulnerability and willingness to learn is growth.
If you're seasoned teacher. Please consider being a mentor. Unfortunately, finding that willing teacher to sit under your wing may not be easy. However, the encouragement and support from a wiser more experienced teacher can give someone the confidence they need to positively speak into their student's lives.