First of all, I have attended a Pentecostal Church in the past, and have several friends that came from that background. There are several variations within the church. However most have a very legalistic background - and probably this type was more prevalent when your partner was a boy. Those that are very involved with this religion seem to get part of their identity out of belonging to it and thinking like the group does. (Of course this is pretty prevalent with a lot of religions.)
I said all of that to say this: This pattern fits right in with the Virgo and Sagittarius emphasis in his chart. The underlying premise is that you must believe like they do in order to be "saved". (Sagittarius issue). And underlying that is the belief that you have to do everything "right" - a form of perfectionism. (Virgo issue) I have found that there are those who give lip service to how "good" God is , but their actions point to their inner belief that they think they must get everything right in order to appropriate this goodness. ( I'm not sure if this is coming out like I want it to. I hope you understand) His Virgo ascendant would feed right into this mindset. I feel that his religious upbringing is feeding his power and control issues. This would explain why he "sure lets you know it" when you point out an issue in his religion that you think he's a little off on. Perfectionists HAVE to be right, as if their life depended on it. (Or God would be mad at them if they misinterpreted the Bible) He obviously has a lot of ambivalence regarding the Bible, but also a great love for it. It is possible that he is called to be a spiritual teacher of some sort, since he loves to teach it so much, but that calling will not come to fruition until he heals from some of his issues.
And now on to power and control..... Again, back to the religious stuff... I don't know if you're aware of it, but the Pentecostal (and most "Christian" religions) teach that the woman is to be subservient to the man - that she does what the husband says. Most of the "Christian" religions also taught that a woman wasn't allowed to teach the Bible. (Although this has changed alot in the past couple of decades). So, he may have been brought up to believe that a woman shouldn't have much say in things. Even if he claims to be a "liberated man", childhood training can be very hard to truly break through, especially if Momma AND the Church says so.
From what you said, he seemed to have been very close to, and maybe even idolized his mother. It is sad that he lost her at such a relatively young age.
As regarding his childhood, I think there were certain dynamics at play: First of all, it is a natural tendency that ALL men (and women) have to overcome to break free from seeing the mother as an authority figure - for all children see mother this way. The more entwined with the mother, the harder it is to see that mother is NOT always right, and does NOT always know what is best for you. As long as a man thinks subconsciously that he has to do what "mother" tells him, he will have a problem relating to women - some more than others. For in his mind, a significant female (or female boss) equates to mother being in authority over him. The way it works in a romantic relationship is that he wants the woman to love him, so he will typically set aside his own will to "win"her love (just as his inner child did with his mother) With some men, this phase can last a long time, and with others it "flip-switches" at some point. And the thing is, that if they're relating this way, they're not being authentic with themselves OR their partners. This naturally results in a build-up of anger, either continually expressed or suppressed or a combination of back and forth.
I'm trying to put you in his mindset, so that you can understand where HE is coming from,and thereby change YOUR pattern of relating. So, you've got the underlying thing with men - of seeing a mother/romantic interest as an authority figure - anger. Then you have the competing teaching of the church that a man is an authority over the woman. The woman does not comply - more anger. In reality, every person, whether male or female is their own authority AS they are submitted to walking in love. Unconditional love is the only true authority. (But unconditional love has boundaries, and does not allow oneself to be walked on - which is a big thing that "love" preachers leave out.)
It is very difficult for many people to acknowledge the faults of their parents, and therefore they do not see them as they truly are. Unfortunately, until you see who they are, warts and all, and then have compassion on them, you are still tied to them. The more blinders you have on - the more you're tied. Your partner's Moon is in Taurus in the 9th. Taurus Moons tend to get very attached to people(esp. mother), tendency to be stubborn, and resistant to change. They can also hold dogmatic opinions. This in combination with the 9th house, which is Sag territory, would be the makings of one very stubborn about their religious beliefs, and probably one's opinions in general.
Then, add in to that mix the fact that he lost his mother relatively young. Human tendency is to idolize the person who was lost. This would make it even harder for him to admit that his mother was not the authority that she more than likely projected herself to be in his life, or that the teachings she subscribed to and taught him were not entirely true. It would probably feel to him that he was betraying her or not respecting her. Yet this is vital for his healing to be able to see his mother clearly, and not through the eyes of a child.
I've said all of this without studying your charts together, but just what I know from experience, and from studying his chart. I intend to study this further, but am feeling under the weather right now, and my current mind is not conducive to study. I will have to get back to you. However, I did look at your chart briefly. The things that immediately stuck out to me was the Sun/Saturn opposition in the 12/6th houses in Libra/Aries. This polarity has to do with being authentic with a partner, treating the other as you would want to be treated - and overcoming codependency. However, it is in the 12/6th, instead of the natural domain of 1/7 houses. This probably has to do with the issue of service to the other - and balance of that, and any subconscious motivations or beliefs that are sabotaging that balance.
Also, you have Mars in Sag in the 3rd house, which basically adds up to your style of communication being very much like one who always has to be right, as well. The situation may be that you have two people who are very concerned with being "right".
If any of what I've said rings true, then I think you're already starting to see some of the underlying dynamics of your relationship, and why you seem to fight all of the time. Also, the Virgo/Pisces eclipsesarelooming near, and Mars just crossed, in the past week ,the eclipse point of the 3-14-06 Virgo/Pisces eclipse. This may partially explain why these issues are getting pushed to the forefront at this time, and may explain some of his depression. He probably is really feeling the "pull" between the two polarities right now.
As I said, I will look into this further, and study your chart as I am able- hopefully tomorrow, or within the next few days. I am recovering from a long illness. I also have problems with my thinking, and have to study "when the muse lights on me", so to speak.