It’s called assurance!

“But what does it say? “The word is near you, in your mouth and in your heart” (that is, the word of faith which we preach): that if you confess with your mouth the Lord Jesus and believe in your heart that God has raised Him from the dead, you will be saved. For with the heart one believes unto righteousness, and with the mouth confession is made unto salvation.” ‭‭Romans‬ ‭10‬:‭8‬-‭10‬ ‭NKJV‬‬ https://bible.com/bible/114/rom.10.8-10.NKJV

It’s called assurance buddy. Read the Bible.