Every single person desires God, how we acknowledge it, respond to and the time we realize it, differs. We desire God because we are spirits, and our spirit beget His, our frequency is always in tune with His whether we choose in a moment in time to live through that truth or not. He is ever present and omnipotent. We desire him because He is always with us (Mat 28:20), reading this as you are (even as also, He fortold it). Our desire for Him is also because He desires us first (John 15:16). We need not make mental efforts to access Him because His calling on who He made is that apparent and magnetic and causes us to desire Him. The time will come for those who haven't encountered Him, and the time will never end for those who think they've desired Him enough and have a track record of putting effort because we are not the source of the desire for God.