Bible Discussion Thread

It's amazing there so many different "beliefs" systems in the Christian community, especially when Jesus taught only one "specific" gospel to his disciples. Jesus then told his disciples to go and teach THAT SPECIFIC GOSPEL to the world. In one corner we have people who seek salvation by "only believing" on or in Jesus Christ. In the other corner we have those are accused of being "legalistic" in their approach to obtain salvation. Question- where do we find the VERY FIRST instructions as to obtaining salvation??
Was in it St John, or Romans, maybe Ephesians? No, it was in Acts. In Acts , Peter gave specific instructions how to obtain salvation. Christians today would probably call Peter a "legalist" because he told the men to "do" a "work". Peter told them to repent, and BE BAPTIZED for the remission of their sins. IF baptism is actually a work of man, then Peter had no right to instruct those men to be baptized. Question--was Peter actually a "legalist"? Is baptism a "self righteous work" of man, or is it REALLY for the REMMISION of sins??. Should Peter instructed those men to ONLY BELIEVE on Jesus? Naturally everyone has their "own belief system". BUT does their belief system acre with the Bible.??