Christians are to be open-minded on many issues, but not on how we are saved from sin. Our focus should be on Jesus, whom God offered as the way to have an eternal relationship with himself. God chose them, not to play favorites, but so that they would tell the world about his plan of salvation. For centuries the Jews had been learning about God by obeying his laws, keeping his feasts, and living according to his moral principles. Of course, the disciples and the great apostle Paul were faithful Jews who recognized in Jesus God's most precious gift to the human race.
Some sins seem bigger than others because their obvious consequences are much more serious.
Murder, for example, seems to us to be worse than hatred, and adultery seems worse than lust. But this does not mean that because we do lesser sins we deserve eternal life. All sin makes us sinners, and all sin cuts us off from our holy God. They all separate us from God, but they all can be forgiven. Consider your life and then turn away from everything in it that is contrary to what God wants.