If a non-Christian asked you how you knew God was real, what would your response be?

The heavens declare the glory of God,
and the sky above proclaims his handiwork. -- Psalm 19:1

Yet he did not leave himself without witness, for he did good by giving you rains from heaven and fruitful seasons, satisfying your hearts with food and gladness.” -- Acts 14:17

When I look at your heavens, the work of your fingers,
the moon and the stars, which you have set in place,
what is man that you are mindful of him,
and the son of man that you care for him? -- Psalm 8:3, 4

For his invisible attributes, namely, his eternal power and divine nature, have been clearly perceived, ever since the creation of the world, in the things that have been made. So they are without excuse. -- Romans 1:20