God’s side: “God so loved the world, that He gave His only begotten Son.”
Your side: “That whosoever believeth in Him should not perish, but have everlasting life.”
Notice: God loved-God gave. The loving and giving are God’s side; the believing and having are your side.
Many people try to change sides with God. They try to do the loving and giving, and expect Him to do the believing and having! That is, they are trying to love God and trying to serve God. Then they hope He will believe in their earnestness and accept their good works and give them eternal life in return.
You must keep on your own side of the line. God has loved you and given His Son for you; that is His part. Now, do you really believe in Him? If so, then God says you shall not perish, but have here now—everlasting life. It’s all in that verse.