"Someone might argue, 'If my falsehood enhances God's truthfulness and so increases his glory, why am I still condemned as a sinner?" Why not say — as we are being slanderously reported as saying and as some claim that we say — "Let us do evil that good may result?" Their condemnation is deserved. -- Romans 3:7-8
Paul never actually met Yeshua as a living man. Paul's only claim to knowledge of Jesus was through a supposed meeting between Paul and the ghost of Jesus. In fact, before this meeting Paul was actually known as Saul of Tarsus and actively participated in the persecution of the early cult following of Jesus and its followers. Paul almost singlehandedly built the Christian faith and the early Christian church. The codes of conduct governing Christianity all come from the Pauline letters to the churches at Corinth, Ephesus, Rome, and to the Colossians.
Paul outlined that salvation came through believing only in Jesus' death and resurrection, and therefore in one whoosh of a pen completely overturned what Jesus had to say about the importance of observing the law to the letter.