I John 5:9  If we receive the witness of men, the witness of God is greater: for this is the witness of God which he hath testified of his Son.
10  He that believeth on the Son of God hath the witness in himself: he that believeth not God hath made him a liar; because he believeth not the record that God gave of his Son.
11  And this is the record, that God hath given to us eternal life, and this life is in his Son.
12  He that hath the Son hath life; and he that hath not the Son of God hath not life.

God does not want us to put the word of men above His Word. It is good to receive the word of good men. We cannot isolate ourselves from all people. We need to use God’s Word as our authority and decide who we will associate with based on the Word of God. Those who are saved are called to be a light in the world. We are also called to fellowship with other saints. We need some Godly people in our lives to sharpen us in our walk with God. Good Bible study is important. Good Bible study does not look for consensus. Good Bible study accepts the Word of God as the authority and then teaches this truth to the minds of men. All people must come under the authority of God’s Word. All people will come under that authority one day. For many it will be too late to benefit them.
In our text, John wrote that God testified of His Son. God the Father declared that Jesus Christ was His beloved Son. He further stated that He was well pleased in Him. There was no need to put a caveat in the relationship between God the Father and God the Son. There was no need to whitewash sin to make it seem as though they were in agreement. There was and is a perfect relationship between God the Father and God the Son.
It is a blessing to be adopted into that family. It is a blessing to know the true God through His Son, the Lord Jesus Christ.
In verse 10 we are reminded that the person who believes in the Son of God has the witness in himself. Jesus promised to send another Comforter:

John 14:16  And I will pray the Father, and he shall give you another Comforter, that he may abide with you for ever;
17  Even the Spirit of truth; whom the world cannot receive, because it seeth him not, neither knoweth him: but ye know him; for he dwelleth with you, and shall be in you.

The Holy Spirit indwells every born again Christian. He testifies of the Son to the heart of the saint. He is given to guide the true child of God into all truth. As the true child of God is involved in a true local church, he will grow in the truth.
The person who does not believe God makes Him a liar. It is not that God is a liar. However, the person who rejects Him, suggests that God is a liar. We can never find fault with God. Those who are arrogant might suggest that they disagree with something that God says, but no person will ever legitimately accuse God of any sin.
God has given us an accurate record of His Son. God gave us four Gospels, each of which gives us a record of His Son while He was on this earth. Each of the Gospels has a few different things they contribute to the life of Jesus Christ. None of them contradict another. They were written by holy men chosen by God. There are many more things that could have been written about Jesus Christ, but they are not necessary. The epistles also give further detail regarding Jesus Christ and salvation and walking with God. All of it is for our benefit.
The Old Testament gives prophecies regarding Jesus Christ. They too complement one another. We have all that we need to know about God and Jesus Christ. Unless a person is saved, they will not make sense of much of what the Bible says.
In verse 11, we are again reminded of the record. The written Word of God is the record. We need that record. We cannot trust the perversions. They give an insufficient and corrupted account of the record. Eternal life is in His Son. Jesus Christ is the only Saviour. Apart from His salvation, we cannot have eternal life.
In verse 12 we are reminded that if a person has the Son, that person has life. Our world offers many things that they suggest are needed to have life. The fact is that life is found in knowing Jesus Christ as Saviour and Lord. The more we get to know Him, the more we will rejoice in His gift of life. Those who want a careless relationship with Him will miss out on blessings.
In the record of John’s Gospel, we find that Thomas chose not to be with the other disciples at times. We are not told where he was, but we know he missed out on seeing Jesus after His resurrection. The result was that he did not want to believe that Jesus Christ was alive. He demanded to see Him and to touch the wounds Jesus suffered on the cross. Jesus gave him that opportunity. Jesus also rebuked him for his unbelief. Jesus promised blessings to those who would believe Him without seeing Him.
Today we have the opportunity of believing in Jesus Christ for salvation. If we truly believe in Him, we will want to follow Him. He is the Lord of the true local church. That is the place He has designed for meeting with Him. A person can make up a relationship with Jesus Christ if they choose to. They might even find some satisfaction in doing so. However, when they die, they will discover that their choice was void of reality and most will find themselves at the great white throne judgment. Not a good place to be. The record of truth is available. Avail yourself of that and be blessed.
Pastor Bartel