The fool says in his heart,
“There is no God.”
–Psalm 14:1 (NIV)–

What may be known about God is plain to them, because God has made it plain to them. 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.
–Romans 1:19-20 (NIV)–

The Spirit himself testifies with our spirit 
that we are God’s children.
–Romans 8:16 (NIV)–

Do not grieve the Holy Spirit of God.
–Ephesians 4:30 (NIV)–

Were not our hearts burning within us 
while he talked with us on the road
and opened the Scriptures to us?
–Luke 24:32 (NIV)–