One of the things that sidelines most Christ followers at one point or another is, ‘not knowing’ for sure weather they are saved. You may have called it something else:
•   doubting
•   having questions
•   not knowing ‘for sure’
•   wondering about other religions
•
They all amount to the same thing—not knowing for sure whether or not you are saved.
Which leads to the question: Can anyone really know for sure?
God says, “yes.†You can read it for yourself in I John 5:11-13
11And this is the testimony: God has given us eternal life, and this life is in his Son. 12He who has the Son has life; he who does not have the Son of God does not have life.
Concluding Remarks
13I 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.
Did you catch that? The whole reason John wrote the 5th chapter (the entire letter, actually) was so that we (the readers) could “KNOW.†And this chapter—like all chapters in the entire Word of God—is inspired by God. Hence…
God wants you to know and to live confidently and joyfully in that assurance.
Now, I may not know everything, but I know this for sure!