“I’m not 100% certain I will go to Heaven.” This is the issue with many faiths like Catholicism that lean towards a “works-based faith”. You never really know if your “works” are enough. The entire book of 1 John is about ASSURANCE of salvation. “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 5:13).” You can know 100% that you are going to Heaven, but it’s only through grace alone by faith alone in Christ alone. We are not saved by our works (even in the name of God), we are saved by Christ’s work! All of our assurance is in Him.