Figuring out how to dress for church can be quite the dilemma; in fact, the question itself is likely to get a number of different answers from Christians, depending on who they are, how they interpret their religion and where they go to church. Some Christians will say it doesn't matter what you wear to Church, as long as it is something you can wear out in public. Other Christians might refer a you to wardrobe of jacket, slacks and shoes. Some Christians always wear a suit and tie to church or their "Sunday best." In truth, the way to dress for Church is somewhere right in the middle.
Men's Formal Church Wear
Most men should wear at least a collared shirt, pants, a belt and close-toed shoes to Church, as this is nicer and more respectful then wearing flip-flops, shorts and a ratty T-shirt. If you're going to take the time to attend Church in the first place, then it means you care about it in some way, meaning you should be respectful. That said, wearing a suit and tie is a little much (and possibly unnecessary depending on the denomination, time of service, and age of congregants).
Women's Formal Church Wear
Women should wear attractive dresses and shoes, looking their Sunday best. Wearing high skirts or low cut tops is probably not advisable, as decorum tends to be a priority in most houses of worship; a modest dress that is still attractive, along with shoes, is probably the safest bet.
Ask the Church
As mentioned before, some churches are very lax on dress code and just want you to show up. Ask your pastor, deacon, or minister before you go what their dress code policy is and see what they say. This may also tell you something about the overall tone and attitude of the service you are attending.