Some people choose to be guided by tradition. If a given practice has been around for a long time, it gains acceptability. However, just because something has been around for a long time does not necessarily mean it is right. For years men thought the earth was flat, but they were wrong.
Some people are guided by what they feel in their hearts. The Proverb writer stated, "There is a way which seemeth right unto a man; but the end thereof are the ways of death" (Proverbs 14:12; also read Jeremiah 10:23). "I think" or "I feel in my heart" are not correct standards of authority. Some men accept the majority as being correct. Where was the majority when the flood came? Jesus said the majority will be lost (Matthew 7:13,14). The majority is not necessarily correct.
Some accept their preacher as being the authority. Whatever their preacher says, they believe. However, the Bible teaches, "Beloved, believe not every spirit, but try the spirits whether they are of God: because many false prophets are gone out into the world" (I John 4:1). Just because a preacher may say something to be the truth does not necessarily mean it is the truth. Follow the example of those of Berea who searched the Scriptures daily to see if what was being taught them was the truth (Acts 17:10,11).
Some accept their creed books, annual conferences and councils as being authoritative. Such are not correct standards of authority for more often than not, they are contradictory to the inspired and infallible Word of God. They contain the doctrines and commandments of men, which when followed render one's service to God in vain (Matthew 15:9). The Bible is the only infallible guide we have in our possession (II Tim. 3:16,17).
Christ and His Testament is the correct standard of authority. All authority in heaven and in earth has been given unto Christ (Matthew 28:18). He is the One that men are to listen to (Deuteronomy 18:18-19; Acts 3:22,23; Matthew 17:1-5; John 12:48). His Testament is complete, final and all-sufficient (John 16:13; Jude 3). Religious practices are to be based upon His Word (I Peter 4:11).
In view of the above, can you give book, chapter and verse from the New Testament for what you practice in matters of religion? By what authority do you do the things which you do?