A Jewish person who was raised without the benefit of a Jewish education can not be held accountable for his lack of observance which stems from ignorance. This is much like the Halachic status of a “tinok shenishba bein ha-amim” – a Jewish child raised in captivity amongst non-Jews, who due to no fault of his own is oblivious to Jewish study and practice. 

An example is given of a person climbing a ladder. The person is not expected to reach the top rung of the ladder with his first step

Even upon learning, however, one does not go from 0 to 613 overnight. When someone is made aware of Torah and mitzvahs and decides to become more observant, s/he is not immediately expected to do all the mitzvahs. One becomes more obligated as one becomes more learned—each person following his/her own individual pace.

It is advisable to be in close contact with a spiritual advisor (a rabbi, Rebbetzin, etc.), who can objectively assist in determining the proper pace.

An example is given of a person climbing a ladder. The person is not expected to reach the top rung of the ladder with his first step. That would be impossible, and such an attempt would be an exercise in futility.

Instead, the wise climber slowly and methodically climbs the ladder, one rung at a time—but never losing sight of his ultimate goal, reaching the top rung.