Am I required to make up missed prayers, fasts, etc… if I didn’t believe in Islam, didn’t consider myself a Muslim, although I was born in a Muslim family and publicly called myself a Muslim?
In the Name of Allah, the Most Merciful and Compassionate
Obligatory prayers, fastings, charities, etc… are only obligatory on adult muslims who have their sanity intact. [Ibn ‘Abidin, Radd al-Muhtar]
If you were not Muslim at that time, you are not required to make up any obligations. If these obligations were missed prior to your reaching puberty, you are not obliged to make them up. [Ibid.]
Embracing Faith By One’s Own Choice
It is common for people to follow the religion of their parents, even if just by name. This also applies to Muslims. For such people, there comes a time where they decide to embrace their own faith by their own volition.
When this occurs, the blessing of Islam and the profoundness of what it means to have a relationship with one’s Creator begin to open up upon the heart. The serenity that is experienced at the onset of one’s self embracement and realization of one’s purpose in life is hard to explain and almost impossible to show it the gratitude it deserves.
Knowledge, the Pillar of Faith
It seems from your question, even though you may not have been muslim then, that now you are in the process of reconnecting to Islam. I pray that Allah Most High blesses you and put the light of guidance in your heart. The first and most important step for anyone in your situation is to, slowly but methodically, seek a deeper understanding of Islamic knowledge.
Begin with the sciences of Islamic beliefs and Islamic jurisprudence. Consider the classes offered here at www.seekersguidance.org/courses
In your seeking of knowledge and your furthering of your connection with your religion, strive for moderation, consistency, and quality over quantity. Most importantly, ask Allah Most High to assist you and bless you in all that you seek.
Hope this helps
Allah knows best
[Shaykh] Yusuf Weltch
Checked and Approved by Shaykh Faraz Rabbani