Why have they chosen Islam?

, 41 years. I noticed that Christianity could be summarized into a not very much convincing story, i. e., that God crucified his only son in order to save us and that if you believe in this crucifixion, you are saved. I could not see why God should kill His only son
since killing is prohibited by God Himself. God orders us not to kill, but He Himself killed His own son. I could not either swallow the crucifixion of Jesus, assuming it happened, as a means to salvation because I could not figure out how crucifying an innocent person would lead to others’ salvation. I used to hear about Islam, and I was
informed that Islam does negate Jesus’ crucifixion and does not accept the theory of
salvation through crucifixion. The Islamic principle that salvation is guaranteed only through faith and good deeds makes more sense to me.