A surety is a guarantee of something. For this reason the Lord says to never become surety for someone else’s debts. However, the Lord has given us a surety for our salvation, that He will come back for us. We can know for sure that we have an eternal home with Him.
I John 5:6-12This is the One who came by water and blood, Jesus Christ; not with the water only, but with the water and with the blood. It is the Spirit who testifies, because the Spirit is the truth.For there are three that testify: the Spirit and the water and the blood; and the three are in agreement. If we receive the testimony of men, the testimony of God is greater; for the testimony of God is this, that He has testified concerning His Son.The one who believes in the Son of God has the testimony in himself; the one who does not believe God has made Him a liar, because he has not believed in the testimony that God has given concerning His Son. And the testimony is this, that God has given us eternal life, and this life is in His Son. He who has the Son has the life; he who does not have the Son of God does not have the life.
The water means that He was born into this world as a human being.For this reason the Lord says that someone must be born of water to become a Christian. This is the actual physical birth. Someone must be born physically to be able to be born again spiritually.
John 3:8 Jesus answered, “Truly, truly, I say to you, unless one is born of water and the Spirit he cannot enter into the kingdom of God.
The blood is the testimony of the cross that He died and rose again.
I Corinthians 15:3-6 For I delivered to you as of first importance what I also received, that Christ died for our sins according to the Scriptures, and that He was buried, and that He was raised on the third day according to the Scriptures, and that He appeared to Cephas, then to the twelve. After that He appeared to more than five hundred brethren at one time, most of whom remain until now, but some have fallen asleep;
The testimony of God is when He spoke from heaven that Jesus was His beloved Son. These are all in agreement that Jesus is the Son of God.
Matthew 3:17 and behold, a voice out of the heavens said, “This is My beloved Son, in whom I am well-pleased.”
However, for those who believe in Him, He has also given another testimony and that is His Holy Spirit. His Spirit bears witness with our Spirit that we are His child.
Romans 8:16 The Spirit Himself testifies with our spirit that we are children of God,
He is coming again and will come for those who believe in Him.
I Thessalonians 4:14-17 For if we believe that Jesus died and rose again, even so God will bring with Him those who have fallen asleep in Jesus. For this we say to you by the word of the Lord, that we who are alive and remain until the coming of the Lord, will not precede those who have fallen asleep. For the Lord Himself will descend from heaven with a shout, with the voice of the archangel and with the trumpet of God, and the dead in Christ will rise first. Then we who are alive and remain will be caught up together with them in the clouds to meet the Lord in the air, and so we shall always be with the Lord.
We have the testimony and we have the surety of our salvation. When He comes again for those who belong to Him we have the promise that He will take us with Him. The guarantee of our salvation is the Holy Spirit that He gives to us when we become a Christian.
Ephesians 1:13,14 In Him, you also, after listening to the message of truth, the gospel of your salvation—having also believed, you were sealed in Him with the Holy Spirit of promise,who is given as a pledge of our inheritance, with a view to the redemption of God’s own possession, to the praise of His glory.
You belong to Him if His Spirit lives within you. If you do not know if the Holy Spirit is within you then there is a possibility that He has not come to live within you. Give your life to Him and ask Him to come in and take possession of your life. You can trust Him completely. He loves you perfectly. You can know for sure that you are His if you have Jesus living in you through the Holy Spirit.
I John 5:13 These things I have written to you who believe in the name of the Son of God, so that you may know that you have eternal life.