I think, crescent, that it's both explicit and implicit. As you say, Jesus taught that the 2 greatest commandments are
to love the Lord, your God, with all your heart mind strength and soul
and
to love your neighbour AS YOURSELF
He says that these two commands are the summation of the whole of the Law and the Prophets.
that's a really, really tall order. When you put it together with the new commandment that Jesus gave us - to love one another as I have loved you - and all his teachings on service (the greatest shall be least and the least greatest, the Son of Man came not to be served but to serve, etc.) it has a great deal of force behind it. Service and justice should never be optional for a Christian, they are central to the faith. For me, it's all kind of summed up in the Golden Rule -do unto others as you would have them do unto you. I would like to hope that if was hungry, someone would feed me, if I was sick, someone would help me, if I was lonely, someone would befriend me, so this is what I try to do. but it's so much more than that.
It all means that we should guard our tongues and not speak nastily to people, that we should always try to be king and welcoming, that we should try to be considerate, empathetic and non judgemental -
"Do not judge, or you too will be judged. For in the same way as you judge others, you will be judged, and with the measure you use, it will be measured to you. ?Why do you look at the speck of sawdust in your brother?s eye and pay no attention to the plank in your own eye?"
It's also incumbent on us to be law abiding, tax-paying citizens. when asked about paying taxes to the occupying Romans, Jesus told us to "render unto Caesar, Caesar's due."
I think that these things are also implicit in Jesus' actions - he healed people from all sorts of backgrounds, spent time with those whom others avoided, even his disciples were ordinary people who had no real importance in their society or who were actively disliked (Matthew was a tax collector). DO you know the story of Zacchaeus the tax collector? I think the lessons to be taken from that make it obvious that we should be fair, honest and try to make things better for those around us (amongst other things.)
To be honest, we all fall far short of this ideal, but it shouldn't stop us trying to live up to it or working towards it.
One of the things that makes Jesus seem more real to me is that the Gospels often talk about His emotions. He feels sorry for the crowds that follow him, he is moved to tears by the grief of his friends, he is tormented by fear and doubt in Gethsemane and loads more. it shows me that Jesus understood and really felt what it is to be human.