Is it necessary to change the name "Abdul Jalal," and is it sufficient to use the name "Jalal" to avoid a radical change, and what other advice is there regarding this matter?

"Al-Jalal" (The Majesty) is not one of the names of Allah Almighty; rather, it is a verbal noun indicating عظَمَة (grandeur/greatness). "Al-Jaleel" (The Majestic) is the اسم فاعل (active participle) derived from it, and scholars have differed on whether it is considered a name of Allah Almighty.

As for naming someone "Abd Al-Jalal" (Servant of Al-Jalal), it is not permissible because "Al-Jalal" is not one of Allah Almighty's names.

However, naming someone simply "Jalal" (majesty/grandeur) is permissible and is not considered an imitation of Allah Almighty's attribute "Al-Jalal," which comes with the definite article "al" (الـ).

It is preferable to choose names beloved to Allah, such as "Abdullah" (Servant of Allah) and "Abdul-Rahman" (Servant of the Most Merciful), or the names of prophets and righteous people.