And, something I wrote a few years to answer the question. I may have posted this before...
I was raised a well churched Episcopalian. My great grandfather, the original progenitor of my name, was an Episcopalian minister in Baltimore. My late uncle, after whom I was named, was the Episcopalian bishop of Alabama and the Gulf Coast. My mother, she should live good and fulfilling years, served in every position that she was able in the church. My late father was on the board of the church and of the local Episcopalian private school. One of my brothers, at age 50, changing from a very successful career as a Vice President in General Dynamics, became an Episcopalian minister and has a parish in Massachusetts. We all sang in the choir; were acolytes; part of the youth group and went to Sunday school. The church was a central part of our life.
When I was about 11 years old, I asked my family minister about the Resurrection and the Trinity. I told him that I didn't get it. He said "I don't think it's meant to be taken literally..." This blew my little mind and thus began my slippery slope... By the time I was 16, I was already reading about Eastern religions and New Age philosophies. By the time I was 18, I was fully embracing hippiedom in full flower and form - sex, drugs, and rock and roll (and much music that I really liked); I accompanied these hedonistic explorations with a keen interest in all things spiritual.
As I hitchhiked my way back and forth across North America, I danced with the Hare Krishnas and read their Bhagavad Gita As Is. I later read the whole Ramayana in English. I read the Vedas and the Upanishads. I read Pantajali's yoga sutras. I visited many communes including the Farm in Tennessee.
I studied "The Way," a very intense Fundamentalist Christian Cult. I meditated on the Guru MaharahJi the little fat Indian boy who was the Divine Light Mission, receiving the "secret" knowledge. I played with the Wiccans, learned about Druidism and danced naked under the Moon. I engaged in peyote and psilocybin mushroom spiritual rituals. I Sat with the late Chayom Trungpa Rinpoche, a Tibetan Buddhist Master at Naropa Institute in Colorado. I studied Tai Chi Chuan with Maggie Newman. I read all of Carlos Castaneda; Alan Watts; the Baba Ram Dass; Herman Hesse; Doris Lessing; Idries Shah, and everyone else... And the Tao Te Ching of Lao Tsu. I became adept at the I Ching, Tarot and astrology. I studied parapsychology. I learned Taoism and EST and Silva Mind Control. I learned the various schools of Buddhism and tried Zen. Sensory Deprivation tanks... Tantric Sex...
Probably a few other things that do not come immediately to mind...
After college, I joined a cult in San Francisco that studied the various teachings of Gurdjieff, Ouspensky, Nicoll and Collins... A Fourth Way School as it were... I kept that up for about five years, studying everything under the sun from Homer to Socrates to the bible to the Koran to the Christian schools of monasticism and architecture to Shakepeare to music - all of the esoteric ideas behind all and everything...
And, one thing I took away from all of this was that we all choose to be born as what we are; who we are; and what religion we are born into...
And, that in order to fulfill one's spiritual destiny one should study and practice their own religion - go whole hog and pay the postage...
So I did.
I joined my local Episcopalian Church; was on the Vestry; was a Lay Minister; went to Bible Study every week; taught Sunday School; sang in the choir; and got involved in the church hierarchy and conventions. My minister was a young evangelical type who went on to "revive" various churches (*An aside - How utterly odd. I just Googled him to find out what happened to him and I find that he was "suspended" in 2006 in Florida for having a long time affair with, obviously, someone in my parish from back in 1986. The article described him as a liberal priest. Not the man that I knew... Life is strange...)
At the same time, my wife, who was Jewish, was doing the same in her Conservative Synagogue.
And I, being the ecumenical sort, would accompany my wife and son to the synagogue on Saturday.
As time went by, having again studied the new testament and inquired and read and learned and looked at everything from all sides, I began to give up on Christianity. It was obvious to me that Jesus was not god and that he never claimed to be. It was also obvious, with my very limited knowledge of Judaism, that the whole idea of Jesus being the Messiah bore no relationship to what Moshiach is or will be in Judaism. It simply didn't make any sense.
And, G-d pulled me to Judaism. There were countless "random" events that were clearly the Hand of G-d directing me (and my family) to be Jewish. It was "basheirt." (Meant to be.)
As the years went by, in 1993 I converted and we became ("ultra") Orthodox Torah observant Jews
And my children and grandchildren are all the same. It's a good life.
I explored many things over my young years and, it wasn't so much that I decided not to be Christian - in spite of my convictions that the Christian Church got it all wrong; Jesus is just all right by me.... - it was much more that G-d chose me to be Jewish.