Can I be certain?
Can I be absolutely certain that I have forgiveness from God and that I have a relationship with Him?
Yes. If you have placed your faith in the person and work of Jesus Christ, you have eternal life.
And this is the testimony: God has given us eternal life, and this life is in his Son. He who has the Son has life; he who does not have the Son of God does not have life. I write these things to you who believe in the name of the Son of God so that you may know that you have eternal life. 1 John 5:11-13