Is it permissible to attend the wedding of a brother who does not pray?

It is permissible to attend the wedding of a brother who does not pray if the absence would not benefit in deterring him from abandoning prayer. He must be advised and called to the truth, and the immense importance of prayer must be explained to him, along with a warning against abandoning it and its punishment in this world and the Hereafter. He should not be forsaken unless it is highly probable that such an action might lead to his repentance and return to prayer.