NO ULTIMATUMS: Anytime a condition is added to the gospel in the form of 'unless you do X, you cannot be saved (v1),' run the other way. It doesn't really matter what X is; anybody suggesting additional works need to be accomplished for your salvation does not understand the essence of Christianity: Jesus Christ has completely finished everything required for you to be saved and live eternally in His Kingdom.
BUT NO RULES DOES NOT MEAN ANYTHING GOES: The Jerusalem Council, as it's come to be known, preserved four rules that both Jewish and Gentile (literally 'ethnic') churches needed to adhere to. This seems like a contradiction to the previous paragraph, that nothing needs to be done to cement your salvation. However, in these four rules, this early council told the church: you have been set apart as children of God, therefore you need to look different than the pagan world, which at the time revolved around these four things. Although our culture is not tempted to eat food sacrificed to idols or drink blood, the gist of this council's guidance remains the same: you are to live according to God's commands, not because your salvation depends on it, but because by faith you realize you have been set apart from the world.
DIG DEEPER: Why were these particular four things chosen? Go back to the story of Noah in Genesis, looking at the condition of the pagan world prior to the flood (Gen 6:5-8) and also the provisions God set forth when God establishes His covenant with Noah in Gen 9:4-7. How is the wickedness of the world similar between Noah's time, the Roman culture, and today's society? How does God saving Noah and establishing a covenant with him correspond to what Christ did for us? Use a study Bible to help understand why this concept of blood was such a big deal.
YOU HAVE TO LOVE YOUR CHRISTIAN BROTHERS, BUT YOU DON'T ALWAYS HAVE TO LIKE 'EM: Paul & Barnabas are two giants of the faith, but they had very conflicting styles that ultimately drove them in separate directions. It's ironic that this split occurs right after the Jerusalem Council unifies the church with their decision. Even in our day, the Christian Church is unified, even if the effects of living as saved sinners often causes individual churches to sometimes take separate paths.
ACKNOWLEDGE WHO GOD IS: God knows your heart and has accepted you by His Holy Spirit and has purified your heart by faith alone (v8-9).
ALIGN YOUR LIFE WITH GOD'S WILL: Pray that your life will reflect God's commands, and not the ways of the pagan world.
ASK GOD FOR WHAT YOU NEED: Ask for continued Christian unity so that the gospel can be effectively preached from a diversity of churches.