We all want to be liked.  As a part of our desire to relate well with others, we want their approval of what we do.  Every kind of society provides affirmation for people who keep the rules.  The principle is the same for tribes and clubs, professional associations, businesses, sports, religious organisations and even criminal gangs ... keep the rules and all is well, break them and beware.
 
Before Christ, God's people had a law.  But none of them could keep it perfectly and so they were under its curse (Galatians 3:10).  Even after they believed in Jesus, they found it difficult to understand that the redeeming sacrifice of Christ bought, for believers, freedom from the rules and punishments of the law.  The same was true for new Christians from pagan backgrounds (Galatians 4:8-11).  Old habits are difficult to erase.  Some Jewish believers wanted the Church to keep the old traditions, and looked down on those who did not.  But that sort of teaching was wrong because Christ had redeemed His people from the obligations of the law (Acts 15:22-29)  He paid the cost of all our sins which would keep us out of heaven, and nothing we can do can add to that (Ephesians 2:8-9).
 
However, many people are addicted to religion, because it gives them a sense of achievement when they fulfil the rules, like the Pharisees did.  It is much easier to have a proud heart than faith in Christ which requires our repentance and trusting what Christ has done for us.  Even true believers are lured back by those who want them to conform to a style of religious behaviour which is considered 'right' by the majority.  That is not to say we should abandon any practice which builds us up in Christ and promotes true unity in Christ, but they can never make us right with God.  When those things become more important than the grace of Christ, they become idols and cannot serve His kingdom.  

We need to be encouraged by the Apostle's words and not let the wrong expectations of others deflect us from wholeheartedly trusting in the grace of Christ, being free to live in a dynamic relationship with Him.  It is only His approval which matters!