Buddhist precepts and suppression

In the Buddhist precept it teaches us to 'abstain' and 'refrain'. How is this abstention is different to suppression? It's good to practice with understanding and wisdom but most people are still practising, some people are naturally good in practising some precepts but not the other precepts. Is it true there is an element of suppression in the practice until we reach the final goal? Why should someone follow and practice the Buddhist precepts (5, 8, 10 or hundreds of precepts) if there is no suppression?