Rabbi Samson Raphael Hirsch wrote:
“The so-called ‘belief in the existence of God,’ as…philosophers like to express the idea of ‘the first commandment,’ is miles away from what this fundamental verse of Jewish thought and Jewish existence demands from Jewish thought and Jewish life. Not the fact that there is a God, also not that there is only one God, but that this One, unique, true God, is to be my God, that He created and formed me, placed me where I am, and goes on creating and forming me, keeps me, watches over me, leads and guides me; not that my connection with Him should be through ten thousand intermediaries as a chance product of a universe that He brought into being aeons ago, but that every present breath that I draw and every coming moment of my existence is to be a direct gift of His Almightiness and Love, and that I have to live every present and future second of my life solely in His service — in a word, not the knowledge of the existence of God, but the acknowledgement of God as my God, as the exclusive One in whose hands is the disposal of all my fate, and as the exclusive One guide of all my acts, it is only with this, only with the acceptance of this Truth, that I can lay the foundation of a Jewish life. To the demand, ‘I, the Lord, am to be your God,’ there is but one corresponding reply, ‘You are my God’!” 
Rabbi Hirsch uses the “first commandment” to distinguish between mere “philosophical” understanding — i.e. an abstract ‘belief in the existence of God’ — and the loving, personal relationship with God that is the basis of Judaism (Christianity and Islam as well) — i.e. God is “my God;” we have loving, personal contact and interaction with God.
How does Rabbi Hirsch suggest that we come to the conviction that God is “my” God?
Based on this paragraph, it would be by contemplating that “…[God] created and formed me, placed me where I am, and goes on creating and forming me, keeps me, watches over me, leads and guides me; not that my connection with Him should be through ten thousand intermediaries as a chance product of a universe that He brought into being aeons ago, but that every present breath that I draw and every coming moment of my existence is to be a direct gift of His Almightiness and Love…”
Contemplation of such ideas or concepts is called the “intellectual approach to God- Realization”  or “jñana yoga.”
On a grander scale, this is “Hitbonenut” — the spiritual practice of HaBaD Hasidut.
Changing our thinking is admittedly a slow process, especially if we are trying to go about it simply by reading books. It’s aided substantially when we hear these ideas affirmed by someone who has themselves come to a degree of conviction about them. Their confidence in the truth and validity of these ideas earns our own and gives us a “voice” that counters the doubts we experience ourselves.
Another method of approach begins not with a change in ideas, but with actions that assume our loving relationship with God’s Presence and Providence — even if we aren’t fully convinced of that yet. This leads to a change in ideas as well.
Meditation might fall into this category.
For this post, however, I laud and encourage the practice of Breslaver “Hitbodedut” — regular times of speaking with God privately. Those who practice this come to a level of experience and faith that brings about changes in ideas as well:
“Last month when our tenant moved out, we were unable to get another [tenant] until January, thereby losing a month’s rent when my husband is out of his seasonal work. I have learned to think that only HaShem is the source of our provision and that He uses many ways, but if one is closed, He will use another. So in my Hitbodedut I thanked Him that I knew I did not need to worry as He has shown that He will always provide what we need. I said it would be nice if I had some work to do at home that could fill the gap. The next day I got an email from an author saying I had been recommended as a good transcriptionist and he was in need of having some interview tapes transcribed. He was willing to pay a very good rate. Already I have recouped half the lost month’s income and there are at least as many tapes left to transcribe. It removes so much stress to know we have a Father we can go to who loves us and will always help us according to his wisdom and kindness. I think Rav [Dror Moshe] Cassouto’s teachings that HaShem wants to hear from us, for us to turn to Him in everything, and no matter our past, we can still come close to Him, [have] been great encouragement for me. And when I hear many people say, ‘You shouldn’t think of G-d all the time’ and ‘It’s extreme to pray so much,’ it’s so reassuring that actually the desire to do so is a gift, and God’s mercy that He gives us guidance to come closer to Him in that way. It is so freeing when difficulties come and you don’t know what to do that in a flash of remembrance you can exclaim, ‘Why be downcast? I have a Father! A Father who can do anything, and a Father who cares about me. I can go to Him!’ Last year we were given a cheque that was insufficient and it was going to cause our own account to bounce important payments. My husband tried to arrange making a payment to cover it, but it could not be in time. I went to pray. By the time I finished speaking to HaShem about the situation asking for His help, the bank called to say that they had contacted the other bank and everything had been straightened out and no cheques would bounce and no overdraft charges would be made. These are just two instances, but HaShem is constantly answering prayers both large and small.” 
“I have learned [through doing Hitbodedut] to think that only HaShem is the source of our provision…” What could describe more perfectly the discovery of “my God” so extolled by Rabbi Hirsch?
This also represents “bhakti yoga” — the yoga of devotion.
Sooner or later, one will have to “wrestle” with both the ideas that Rabbi Hirsch specifies and the devotional attitudes and practices that naturally accompany them.
But it is the experience of God in our personal prayer that changes us, brings us to conviction and faith, and illuminates the personal meaning of the ideas that Rabbi Hirsch expresses with such eloquence and power.
 Hirsch, Rabbi S.R.; quoted in Plaut, W.G.; The Torah; A Modern Commentary; URJ Press, © 2006; p. 502 (Dr. Plaut does not provide a more specific citation for the source in R. Hirsch’s own writings)
 Maharishi Mahesh Yogi; The Science of Being and Art of Living; International SRM Publications, © 1966; p. 283