The simple answer is prayer. In the Holy Quran He says:
And when My servants ask thee about Me, say, ‘I am near. I answer the prayer of the supplicant when he prays to Me.’ (2:187)
In another place He says:
And assuredly, We have created man and We know what his mind whispers to him, and We are nearer to him than even his jugular vein. (50:17)
So God is very near. If we pray to him sincerely, we will find him.