The Christian follows the teachings of the Bible (code) to get closer to God (goal); the humanist follows the teachings of modern philosophers like Locke and Mill (code) to try and create a more pleasurable state/society (goal); etc
I think you need to back up here for a second and re-evaluate your thinking for a moment, because you are making a fundamental error here, namely that secular people think differently from religious people. This sort of metathinking, to consider your own thought patterns and structures, is extremely difficult for most people to grasp, but also incredibly useful for debates since it allows you to actually think about what the other side is actually saying and thinking. The fact that you are projecting your own mental structures onto others is very clear here.
There are no teachers or codes in secular morality and ethics.
Oh, there are philosophers and the like, but part of the fundamental structure of secular morality is that it utterly rejects fiat declarations and seeks to construct systems that stem only from naturalistic phenomenon. This runs into the problem that nature does not give a flying fuck what anything actually does outside of a purely mechanistic perspective. The world is cruel and uncaring and utterly without morality on such a level it is actually alien to our normal perspective. However, instead of going down a nihilistic path, we must look at what our instincts are telling us and why we evolved those instincts in the first place. We must also make a judgment on what the actual goals of our system of morality are, which is essentially arbitrary, but the attempt is made to be somewhat less arbitrary than religious sets of morality.
What all of this sums up to is that theoretically, we should be able to burn down all of the works of all the secular philosophers in the world and be able to reconstruct their arguments from scratch. This is in fact what most secular people do, they come to their own conclusions as to what is right and wrong based around the world around them. Let us look at the axioms that they typically use:
1.) From an evolutionary group dynamic perspective, pro-social behaviour increases group fitness typically at the cost of personal fitness, but here is the kicker: a more fit group tends to increase the personal fitness of all members, usually by a larger degree than the cost associated with living in the group instead of living selfishly. This means that we have a multitude of mechanisms both biological and social that serve to encourage pro-social behaviour and discourage anti-social behaviour. Thus from an evolutionary perspective and a purely selfish one, pro-social behaviour is advantageous and should be encouraged.
2.) Our capacity for empathy means that we can vicariously feel the pains and joys of others by comparing their experiences to our own and imagining what is going on in their heads. This means that for non-sociopaths, we tend to feel bad when others suffer and feel good when others succeed. Thus as a purely arbitrary goal, we decide that since we dislike suffering and like joy we should minimize the one and maximize the other. There are of course caveats and subtleties to that to avoid some of the absurdities brought up by certain branches of utilitarianism, but still, that's the goal.
And that is pretty much the axioms that modern secular thinkers use to create their systems of morality. Pro-social behaviour benefits the group and a stronger group means a stronger individual, and suffering sucks so we should minimize that. That is it. There are no prophets, no men coming out of the desert to make proclamations from on high, just a bunch of people starting with those ideas or ideas like them and all independently coming to the same or similar conclusions. It is a completely different basis for morality than religiously based, which is ultimately "Because God said so", which is why it scares so many people: there is no one authority saying that it is so, that it is true. It feels impermanent to people, feels like it is constructed on air and so they recoil from the idea. But guess what: to secularists religious morality is constructed on less than air because they outright reject the authority of the religious figures. For atheists and agnostics, there is nothing in the Bible or any other religious text that will convince them because they do not see the Word of God but a bunch of stories assembled by people in the bronze age to either codify old behaviours or give some advantage for ruling castes over illiterate farmers and shepherds.
So if you want to continue this argument, you need to pause and consider what the secularists are actually thinking and why think the way they think.
I love learning. Teach me. I will listen.
You know, if Christian dogma included a ten-foot tall Jesus walking around in battle armor and smashing retarded cultists with a gaint mace, I might just convert - Noble Ire on Jesus smashing Scientologists