Charles Spurgeon Commentary 1 John 5:13

"These things have I written unto you, that ye may know that ye have eternal life, [even] unto you that believe on the name of the Son of God." — 1 John 5:13 (ASV)

These things have I written to you that believe on the name of the Son of God; that you may know that you have eternal life, and that you may believe on the name of the Son of God.

The apostle said that they did believe, yet he wrote to them that they might believe on the name of the Son of God; because he who believes needs to believe more—more as to matter, and more as to the firmness of the grip of his faith.

There are some who do really believe on Christ who do not know that they have eternal life. They have it, but they scarcely realize that they have it; they are afraid to believe that it is theirs. But, here, the Holy Ghost assures us, through the apostle, that those who believe on the name of the Son of God have eternal life.

Oh, what a comfort this is! Then, you can never perish. There are some who say that you can fall from grace; but how can that be? What kind of life would that be? It would be temporary life. But the Scripture says, He that believeth On the Son hath everlasting life. Then, if it is everlasting, it is everlasting, and there cannot be any end to it.

Our Lord Jesus Christ said to the woman at the well of Sychar, Whosoever drinketh of the water that I shall give him shall never thirst; but the water that I shall give him shall be in him a well of water springing up into everlasting life.