When a man does not circumcise his sons out of fearing harm or under the pretext that it is changing the creation of Allaah, then what is the Sharee'ah ruling? May Allaah reward you.
All perfect praise be to Allaah, the Lord of the worlds. I testify that there is none worthy of worship except Allaah and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and Messenger.
Circumcision for males is obligatory according to the majority of scholars. Abandoning circumcision out of fear that harm will afflict his sons is not a Sharee'ah-approved justification, unless this fear is justified by the statement of a trustworthy physician who decided that circumcision would be harmful to his son, then it would be permissible not to circumcise him.
As for abandoning circumcision under the pretext that it is changing the creation of Allaah, the Sharee'ah evidence indicates that it is exempted. An-Nawawi said: "Circumcision, branding and similar actions are exempted. Other actions, however, are included in the general forbiddance and dispraise."
Allaah Knows best.