What is a Strong Christian

[OpenYourEyes]

I believe that Jesus made a distinction between weak and strong Christians (Gospel of Mark 4:14-20). But yet, when I've made the distinction, it seems to be a shock to some former Christians, as if all Christians are made the same just because they carry the label 'Christian'. This is why I emphasize the importance of weak vs. strong Christian, and of course the weak Christians would likely be more prone to fall away from the faith.

So here's my working definition of a 'strong Christian':
A Christian who has a firm foundation for why they believe. It's also a Christian who delves into Christianity from not only a spiritual perspective, but also from an intellectual perspective (when there is opportunity for such - exception poor countries, etc).

Although many former Christians like to say that they did the research or that they "truly believed", but all this is a claim unless they were able to answer the questions of why they believed and provide an answer, something more than just saying their family raised them into the faith.

How does Christianity relate to philosophy and science?