Answer: The search for religious truth - Christian: he learns by his mistakes, his diligence and God's grace make possible for him to enter Heaven.
Resistance and the inability to adapt to change - Obstinate: refuses to accompany Christian, and mocks him for going on a journey.
Humanity's weak will and lack of resolution - Pliable: he is frustrated with the difficulties of the journey, and leaves Christian.
God's ability to guide humans by sending messengers - Evangelist: he instructs Christian on how to get rid of the burden, brings good news, which lead Christian to salvation.
Step-by-step explanation: