Firstly, humans have the intellectual capacity to deduce from the vast, beautiful creation surrounding us that there is an invisible creator. Nobody believes that a car, a watch, or a paper clip just happened; there always has to be a creator. 

This is evidence from Paul statement in the New Testament:

Romans 1:20-21 (NIV)

20. For since the creation of the world God’s invisible qualities his eternal power and divine nature have been clearly seen, being understood from what has been made, so that people are without excuse.

21. For although they knew God, they neither glorified him as God nor gave thanks to him, but their thinking became futile and their foolish hearts were darkened.

In verse 20 ~ Paul affirms that we will all be without excuse before God because we can experience the extent of His power and divine nature through creation alone.

In verse 21 ~ Paul continues to say some Humans have ignored this very evidence and have instead rejected His existence in love for their own wicked deeds.

This is true of all who have disregarded the existence of God, as they desire the darkness more than acknowledging the presence of a Holy God.

This is the burden of Romans chapter 1, that in the light of all the evidence available no one can claim ignorance of God as an excuse for refusing to honor Him or be grateful to Him. 

Psalm 19:1 (NKJV)

The heavens declare the glory of God; And the firmament shows His handiwork.

Another good argument for the existence of God is the complexity with which creation is designed, allowing us to conclude on His power and knowledge.

Still, it does not give us any information about His character (e.g., love, life, mercy, goodness).

The Bible has been given to us for this purpose, to know Him. Therefore, if you want to know God in His fullness, you should read the scriptures to unfold His Nature and His divine plan for you.