Dear "Masked',
May I suggest the following...
1) Study the proofs of the existence of God. 'Abdu'l-Bahá says that we should know these proofs not merely through "susceptibilities" but through rational proofs. Some Answered Questions, Chapters
1 and
2 introduces this (though many other Writings complement and explain this further--I have referred to some
here--see the "Further References" section of Chapters 1 and 2).. An important side-topic is to read what the Writings have to say about the suffering of innocents, as this is often the real reason why people question God's existence (if not because they understandably reject the existence of a kind of "God" some people ridiculously imagine).
2) There is no contradiction with true science and true religion. Anyone who says otherwise vastly underestimates the greatness of God. So do not hesitate to question religionists' understanding of true religion (including other Bahá'ís) and do not hesitate to question some scientists' confident assertions about religion. Go ahead and ask here, if you like, maybe people here can help...
3) The House of Justice has wonderfully summarized for us six basic prerequisites for spiritual growth. I think (and feel from my own experience) that when one neglects any of these areas, that one's spiritual life will truly suffer. These are summarized
here. To the extent that I practice it, I also feel that (the sacrifice of) early morning prayer is particularly helpful to the seeker (as Bahá'u'lláh says in the Kitáb-i-Íqán).
As far as sins, Shoghi Effendi wrote that we all have a dark side, but that she should simply turn our back to it and face the light. God is very, very merciful...He always wants us to return to Him and be happy.
O ye who believe! seek help with patient perseverance and prayer; for God is with those who patiently persevere.
(Qur'án 2:153)
Brett