I am visiting my worldly family right now and plan to be here for the next few days. I would like to at least spread some seed while I am here. I feel as though I could explain the basics of Christianity well enough if someone were already seeking to be a Christian and asked me about it, but I don't know what to do when people are not concerned about being a Christian. My family members tend to focus and worldly things such as what do we have to eat, what is on TV, and clothing. They don't seem to care about being moral, just what makes them feel good or look good. Also, arguments over minor things often break out. It looks as though I need a way to make them realize that they need to turn to God and repent, but I am not quite sure how to do that. Perhaps I should ask them if they are really happy in their current situations or something. Everyone seems to only have minor exposure to anything Christian -- just general ideas and misconceptions. Do you have any advice for me? Any scripture would be helpful.
The best thing you can do for your family is to set an example of godly living and when they bring up topics, then mention what you learned from God. It is just like what Peter told wives to do. "Wives, likewise, be submissive to your own husbands, that even if some do not obey the word, they, without a word, may be won by the conduct of their wives, when they observe your chaste conduct accompanied by fear" (I Peter 3:1-2). When you are close to people examples work better than rebukes. Otherwise, the person begins to think that they can't do anything right because you are constantly pointing all the wrong they are doing. Even just not doing what they do will make them uncomfortable.
Keep in mind, "But avoid foolish and ignorant disputes, knowing that they generate strife. And a servant of the Lord must not quarrel but be gentle to all, able to teach, patient, in humility correcting those who are in opposition, if God perhaps will grant them repentance, so that they may know the truth, and that they may come to their senses and escape the snare of the devil, having been taken captive by him to do his will" (II Timothy 2:23-26). It isn't about you "winning," it is about them wanting to change.
Always be willing to talk about moral issues and the reasons for your choices. As much as possible, direct the person to the Bible, then it won't be just you saying it. If they disagree, they must argue against God (I Peter 4:11).