You could start by working out an answer to a question commonly raised by schoolmates, such as “Why do you believe in God? ”
اِسْتَعِدَّ مَثَلًا لِتُجِيبَ عَنْ أَسْئِلَةٍ يَطْرَحُهَا رِفَاقُكَ عَادَةً ،‏ كَٱلسُّؤَالِ « لِمَ تُؤْمِنُ بِٱللهِ ؟‏ » .‏