An unknown god is not the idols but is the Lord

 Acts17:16-34

 While Paul was waiting for them in Athens, he was greatly distressed to see that the city was full of idols. So he reasoned in the synagogue with both Jews and God-fearing Greeks, as well as in the marketplace day by day with those who happened to be there.

where they said to him, “May we know what this new teaching is that you are presenting?

Paul then stood up in the meeting of the Areopagus and said: “People of Athens! I see that in every way you are very religious. For as I walked around and looked carefully at your objects of worship, I even found an altar with this inscription: to an unknown god. So you are ignorant of the very thing you worship—and this is what I am going to proclaim to you.

The God who made the world and everything in it is the Lord of heaven and earth and does not live in temples built by human hands.

In the past God overlooked such ignorance, but now he commands all people everywhere to repent. For he has set a day when he will judge the world with justice by the man he has appointed. He has given proof of this to everyone by raising him from the dead.”  When they heard about the resurrection of the dead, some of them sneered, but others said, “We want to hear you again on this subject.” Some of the people became followers of Paul and believed. Among them was Dionysius, a member of the Areopagus, also a woman named Damaris, and a number of others.

Why?

Paul explains that the real God won't need a house or anything supported by human beings. All of this world is created by the Lord. 

What we have to do is repent for our sins and know the real love of the Lord.

When we like to know the truth of life, through the Holy Spirit we may understand the truth and the truth God.

How?

Love everyone around me, but let them know the real God in my life. It is difficult, but we do our best and work with the Lord.