So the Gospel deals with these three root issues: guilt, shame and fear. I've pointed these out so that you might see that there is more than one way to relate the Gospel to the unbelievers that you know. You can approach them according to the root issue that they feel the most.
However, to do that you will need to be able to discern where they are in terms of these three. And one way to get to know others is by getting to know yourself. So, a question to ask yourself is this: Which of these three has stood out the most in your own life? Has there been a persistent sense that you are in the wrong and trying to justify yourself to some perceived authority who could forgive or excuse you (guilt/innocence)? Or have you been among those who are looking for approval, maybe feeling unacceptable and unclean (shame/honor)? Or has the problem been that you have felt enslaved by your fears? It's as we get to know ourselves in terms of these root issues that we will be able to sense where others are. Once that happens we can then relate to them in terms of the particular root issue that especially affects them.
Be aware that talking about any of these three in a personal way with someone is something that you will need to do carefully and gently. Approaching someone and just blurting out, 'I see that you are greatly troubled by a sense of shame', may cause that person to react and pull away from you. Pray not only to be able to discern where people are but also to be able to speak gently into their lives.