The Greek word for repent is "metanoia." Metanoia means to change your mind. Our thoughts, the flow of consciousness which determines our behaviors, can change. Metanoia has to do with moral activity, but goes beyond that. Jesus was teaching that we could change our mind about how we treat people. We don’t have to be unforgiving and cynical. We can change our mind about being negative. We can think positive thoughts and walk in faith instead of doubt. We can change our minds about sin. Rather than being caught in the strongholds of consistent habits of lust or selfishness, for example, we can experience freedom and selflessness. Jesus would not have told us to change unless it was possible and attainable. The Bible is full of words that speak about change. Repentance, metamorphosis, transformation, conversion, resurrection, rebirth, renewal, regeneration, healing and transfiguration.
Jesus taught everyone how to become the best version of themselves. Being perfect does not mean doing perfect things. It means to BE perfect. To exist perfectly. So when one makes mistakes - which we all will - we should be truthful to ourselves about ourselves. That's how we exist perfectly.
That's my understanding of the agenda of Jesus Christ.