Religions are different because they teach different things and worship in different ways.
Does it matter how we worship? (Many say it does not.)
"God is a spirit, and those who worship Him must worship in spirit and truth" (John 4:24). Our worship must be spiritual but it must also be according to truth.
Cain and Abel were both offering sacrifices to God, a form of worship in the Old Testament. Abel's was by faith; Cain's was not. (Genesis 4, Hebrews 11:4) Without faith it is impossible to please God (Heb. 11:6). Since faith comes by hearing the word of God (Romans 10:17), and Abel worshiped by faith, it can be concluded that God must have told them what He wanted. They were both worshiping, but Abel worshiped according to truth (God's word). Cain did not and his worship was rejected.
Nadab and Abihu were both worshiping, but they were using a fire that God had not authorized. Even though they were worshiping, it was not pleasing to God and he punished them with their life. (Lev. 10:1-2)
Jesus said of some, “In vain do they worship me, teaching as doctrine the commandments of men” (Matthew 15:9). They were worshiping, but it was “vain”, or useless, because they were worshiping according to the commandments of men. It mattered how they were worshiping.
Jesus said he has “all authority” and the apostles were to teach the things he had commanded them (Matt 28:18-20). If we follow the authority (instructions) of men in our worship, then does Christ have all authority in our lives? Most is not the same as all. Who has the authority in religion?
Paul wrote that his “hearts desire and prayer” was for the salvation of a certain people in Israel. (Romans 10:1-3) Those he was speaking of had “a zeal for God, but not according to knowledge.” They were “ignorant of God’s righteousness” and were “seeking to establish their own righteousness”. They were worshiping, and they were zealous in their worship, but it was not according to truth.
Yes, according to the Bible, it does matter how we worship!
We should be satisfied to worship God in the way His word instructs. We should not add to the word of God, take away from it, or distort it. (Deut. 4:2, Deut 12:32, Prov. 30:5-6, Galatians 1:6-9, Rev. 22:18-19, 1 Cor 4:6, 2 John 9, et al)
Like it says in Numbers 22:18, "I could not go beyond the word of the Lord my God to do less or more!" We should be satisfied to worship as God's word has instructed.
You stated that you sit in church saying to yourself, "I don't believe that". "Nevertheless what saith the scriptures?" (Gal 4:30)
As for baptism, Jesus said, "He that believes and is baptized shall be saved" (Mark 16:16).
What would Jesus have said if he had meant "He that believes and is baptized shall be saved"?
I believe he said what he meant. I believe Jesus! "He that believes not shall be condemned." (Mark 16:16)
When someone asks what they need to do to be saved, why not give the same answer Peter gave in Acts 2:38?
“Reform, and be baptized each of you on the name of Jesus Christ, to remission of sins…” (Young’s Literal Translation)
“Repent ye, and be baptized every one of you in the name of Jesus Christ unto the remission of your sins…” (American Standard Version)
“"Be sorry for your sins and turn from them and be baptized in the name of Jesus Christ, and your sins will be forgiven.” (New Life Version)
“"All of you must turn away from your sins and be baptized in the name of Jesus Christ. Then your sins will be forgiven….” (New International Reader's Version)
(Please read the articles at the first two links below, or if you have time, read the book at the third link. I think you will be glad you did!)