Guys, I will be having prayer group this week and I've asked my backslided Christian friend to join me this week and said okay but he said he's backslided and doesn't really believe in God anymore. I'm here to seek some help from you guys as to what to say to him to convince him that our God is the true and living God who cares and loves Him in the hope that he would return to His embrace. Scriptures might or might not work in this instance but I hoping for some answers that non-Christians or backslided Christians could easily and readily grasp.

Thank you all

“Nevertheless I have somewhat against thee, because thou hast left thy first love. Remember from whence thou art fallen, and repent, and do the first works“;…
For backsliders, there is no easy or readily answer to grasp, rather scripture only gives such instructive warnings.
As for Christ, His followers are volunteers, not draftees; neither is there any flattery to please any; After Christ ended His time in one place, He departed, and it was up to that person to follow Him; Christ was never a people-pleaser.
“No man, having put his hand to the plough, and looking back, is fit for the kingdom of God”.
“For if after they have escaped the pollutions of the world through the knowledge of the Lord and Savior Jesus Christ, they are again entangled therein, and overcome, the latter end is worse than the beginning”.
Below is the only consolation for the backslider, if he is receptive to mildness, then glory to God, but he must return with sincere intent to be restored, and nothing wavering.
“Brethren, if a man be overtaken in a fault, ye which are spiritual, restore such an one in the spirit of meekness; considering thyself, lest thou also be tempted”.
The grace of our Lord Jesus Christ be with you and your friend.