Should a minster counsel a woman by himself? What I mean is should he go over a woman's house by himself to discuss the Bible? Please give me an answer and scriptures to back this up.
Understanding that it is every Christians responsibility to study the Bible with others, there is no scripture, to my knowledge, that would specifically forbid a man to go to a woman's house to study the Bible with her, in fact, I would think that if she wasn't a Christian that it would be the right thing to do to go and teach her the gospel (Matthew 28:18-20).
On the other hand, it would not necessarily be a wise thing to do this alone. It would be a good idea for the teacher to take with him his wife, or if he is not married, an older Christian woman, perhaps an elder's wife (and even the elder himself) to go with him to the study. I don't know of anyone who would object to this provided that those accompanying the teacher didn't unduly interfere in the study. The scripture that I would cite in this regard would be Matthew 10:16, "Behold, I send you forth as sheep in the midst of wolves: be ye therefore wise as serpents, and harmless as doves." We should always be aware not to get ourselves into a situation that might compromise our ability to preach and teach the gospel. A preacher going to a single woman's house could be such a situation, particularly, if that woman had a bad reputation in the community.
In balance to this word of caution, however, it was said of Jesus that he associated with publicans and sinners (Matthew 11:19). Reputation is not everything. We should be willing to do what God tells us to do, even if that would sully our reputation. Evil men may always find ways to entrap Christians in bad situations if that is their desire and they may even "spin" something that is good into something that appears to be bad. However, as Christians, we should not judge according to appearance, but make righteous judgments (John 7:24). The world does not do this, but we must.
I have taught two classes on the subject of personal evangelism, and in each class I recommend, as did Jesus (Mark 6:7), that if you go to study in someone's house, it is wise that you take another person with you. This would be my recommended course of action, however, I wouldn't refuse to teach the gospel to someone who needed it if the only means I could accomplish that would be to meet with them on an individual basis.