I tend to use the word ideology in a narrow and restricted sense, meaning programmatic assertions that make up a socio-political agenda. Taken in that sense, saying Jesus did not teach us an ideology is not lacking anything, but is true to what he teaches, to what he communicates, which is nothing less or other than himself in whom "the whole fullness of deity dwells bodily" (Col. 2:9 ESV). Because of this, the Gospel survives social and political upheaval and is even made stronger, more attractive as a result. The church is never less the church than when we try to make the Gospel a political program, which is not to say that certain Christian commitments don't inform our stance as citizens in a free society. Even then, we become ideological when we take that stance reflexively and/or thoughtlessly, as Carrón said: "because the boss said so. This is not human; it is not human!".
Experience, then, your experience, seeking what you really desire, is what must inform any authentic engagement. This is Giussani's dangerous idea.
I fully recognize that there are two obvious and a few more subtle ways you can take the picture and slogan above. So, don't look to me to clarify it for you.