Matthew 22:23 The same day came to him the Sadducees, which say that there is no resurrection, and asked him,

If there is one issue which points directly to why anyone would not believe in any religion it would have to be the issue of resurrection. If there is no resurrection, what is the point of any religion? I once asked a Buddhist why she was a Buddhist and her reply was, “So that I will be kinder to my fellow man.” My reply to that was, “You do not need religion to do that.”

The issues of an afterlife are not totally unique to Christianity. A desire for immortality is common within natural man. Beliefs of an afterlife vary within different belief systems as to what that looks like and how it comes about. Reincarnation is a form of resurrection with a different method of understanding. It is not seen in these days, so a fair amount of skepticism is to be expected.

1 Corinthians 15:17a And if Christ be not raised, your faith is vain;

Faith fails if there is no resurrection. So how can we know by faith that we believe in a risen Savior? If we do not have a reasonable answer, why should anyone believe our witness?

2 Corinthians 1:20 For all the promises of God in him are yea, and in him Amen, unto the glory of God by us.

2 Peter 1:4 Whereby are given unto us exceeding great and precious promises: that by these ye might be partakers of the divine nature, having escaped the corruption that is in the world through lust.

We believe in the promise of resurrection because He has kept His word in the other promises. It is not that much different than any relationship we develop with mankind. If they keep their word, we gain trust in what they say. Broken trust breaks fellowship. I can say as a faithful witness, God has not broken one promise with me.

Those promises are manifested in Christ and if you do not abide in Christ, those promises are not to you.