God's testimony

“We accept man’s testimony, but God’s testimony is greater because it is the testimony of God, which He has given about His Son.” 1 John 5:9
In a human court, witnesses are called on to testify about things they have seen and heard. When multiple witness accounts agree, the justice system is satisfied that they are telling the truth.
If someone comes to you and tells you to get out of the building immediately because there is a fire and they’ve seen it, you would accept this information as fact and take appropriate action.
Why is it, then, that so many people hear what God has to say concerning His Son, written to us in the Bible, and refuse to believe it?
“And this is the testimony: God has given us eternal life, and this life is in His Son” (1 John 5:11). This is God’s testimony to us: that eternal life is available for all, through Jesus Christ. God’s testimony is greater than man’s, because God is completely incapable of lying. Therefore everything He says is true and trustworthy. John goes on to say, “Anyone who does not believe God has made Him out to be a liar, because he has not believed the testimony God has given about His own Son” (1 John 1:10). You don’t have to verbally call God a liar – if you refuse to believe in Christ for salvation, that’s what you are saying in your heart.