Maintaining a right posture while standing for singing in a church is as important as is singing itself. You have to stand in a way that you add a visible expression to your voice. This makes responses even more effective in response to the lead singer.
Before indulging into singing, you will need to warm up your voice little bit. Since it is high-pitched singing process, you have to make your individual response be heard effectively. It is not possible that you get a cover of some other singers around you, if your voice is not energetic and electric, you have to be heard out loud.
Although remembering notes or lyrics is important in this type of singing, you cannot sing without practice. So it is better to start with some practice and then go on to improve from that level. This is the reason that people start singing on choir where they can gain some confidence before thinking to become a lead singer. Practice and practice alone can help you improve considerably.
While singing you should maintain a proper breathe level. Breathing correctly and comfortably well is as important as standing and maintaining a right body posture. When you practice in group, you can get to know these and other requirements. You can also check with your breathing practice and voice tone while singing alone at home, especially in front of a mirror.
Another important part of Gospel singing is perfection of vibrato. You should be singing in the same tone until very end of pronunciation of each word. Let yourself be heard clearly while singing each word in the choir. There is no chance for cover-up if you sing a half line and leave some words in the end of the line. This is the quality of the singing that it requires an effective response from each person clearly and in the same tone.