Paul wrote to the Galatian Christians because the gospel he preached was being undermined by false teachers and false gospels (Galatians 1:6-9).  He was not a stranger to the new Christians; through his teaching, people were converted and churches had been established.  They should have been grateful to him.  But his place was soon taken by attractive preachers who brought the message of salvation by works – the more you can do for God, the more He will be impressed.  That is not the true gospel.  So, as they threw out Paul’s gospel (given by Jesus Christ), they also threw out their relationship with him.  It was a case of ‘reject the message, reject the messenger’.
 
So Paul reminds them of the relationship they once enjoyed.  Their initial meeting was because his preaching tour had to be diverted due to illness.  Despite his weakness they welcomed him because they were hungry for his message of salvation, by grace and not by works.  Their response to Paul was just as though Jesus Christ had been physically present.

So why, Paul asked, had they turned against the gospel messenger?  He knew the answer, but wanted them to understand how their hearts had been changed as they drifted from Jesus as the only Saviour, and went back to their old habits of trying to impress God.  They moved away from the gospel message.  That is why they had rejected its messenger.  It is the principal reason for persecution (2 Timothy 3:12).
 
Although it is now popular to talk about a ‘spiritual journey’, if you have moved from Jesus as the all-sufficient Saviour – you have gone the wrong way.  Who first led you to know Jesus; have you maintained that fellowship?  Who first taught you how to live for Jesus; have you continued to honour that relationship?  Or have you resented being corrected, and chosen what seemed to you to be a better way, meanwhile telling others how much your teacher has hurt you?  People like that break relationships, because they are resisting the truth.  When that happens, the relationship which suffers most is with Jesus: but there is no better way than to trust Jesus and obey Him ... and be in fellowship with those who told you the truth about Him.