Yes. There is. 1 John 5:9 says, “If we receive the witness of men, the witness of God is greater;…” So I’ll start with the witness of God in Romans 1:18-22:
18 For the wrath of God is revealed from heaven against all ungodliness and unrighteousness of men, who suppress the truth in unrighteousness, 19 because what may be known of God is manifest in them, for God has shown it to them. 20 For since the creation of the world His invisible attributes are clearly seen, being understood by the things that are made, even His eternal power and Godhead, so that they are without excuse, 21 because, although they knew God, they did not glorify Him as God, nor were thankful, but became futile in their thoughts, and their foolish hearts were darkened.22 Professing to be wise, they became fools,
God says further in 1 John 2:22, “Who is a liar but he who denies that Jesus is the Christ? He is antichrist who denies the Father and the Son.” This tells me that God somehow makes the truth of Christ known to those who hear the Gospel, otherwise they wouldn’t be liars for denying Christ, they would just be mistaken.
But there are also human arguments made in favor of God’s existence in general, and of Christianity in particular. For God’s existence in general I use the arguments presented in these two articles:
And for Christianity in particular, I use the arguments presented in these two articles:
Further, I am a Young Earth Creationist, and use the chapters from this online book in opposing Evolution: