"Jesus saith unto him, I am the way, the truth, and the life: no man cometh unto the Father, but by me." John 4:6
If you talk to very many people about their salvation, or read some of the posts on Facebook, you quickly realize that there are a whole lot of opinions and varying beliefs on the subject. Some of the beliefs are so far out there it is hard to believe that anyone could actually believe like that. Some of them are so far fetched, you wonder where they ever heard that. Some of them are just totally wrong.
I am not the authority as to what you have to believe, or what is the right belief, or what is acceptable. The Word of God is the authority. God tells us in His Word who will be and who will not be allowed into heaven. It tells us what He requires and will accept. If you go for a job interview you will discover that there are certain requirements that the employer is looking for and if you don't meet those requirements you will not get hired. It is pretty much that way with anything in life. You can't go to the store and purchase certain items without meeting some requirement. You can't join a club without meeting the club's requirements. So, why do we think we don't have to meet God's requirements for entering into heaven and still go to heaven?
You may be sincere in your belief about Christianity and salvation, but you can be sincerely wrong. And just because you were sincere in your belief doesn't mean that you will get a pass into heaven because you "tired". You have to believe the right thing and then act upon it-- based on what God says. If your belief doesn't line up with His requirements you will not enter into the Kingdom of heaven when you die. It is as simple as that.
He doesn't want you to perish. He wants you to enter in, therefore, He has laid out all that He requires for you to be able to enter into heaven in the Bible. And He has provided the way to be able to do it through His Son Jesus Christ. You can't just enter in because you want to, or because you think you deserve to, or you think your way will get you there, or you are sincere. You will only enter in if you come God's way and meet His requirements.
Have a great day. You can't make your own requirements for entering into heaven. You have to meet God's requirements.