Romans 3:1

Romans 3:1
Quite a few years have passed since Paul wrote these words and the people reading them are quite different now from those he originally wrote them to. Yet I have heard this same sentiment expressed several times about Christianity. If God is just; if God allows into Heaven even non-Christians who earnestly seek Him, why should we even attempt to convert anyone to Christianity? Surely He would condemn people who think they're doing what's right yet are misguided. If God looks on the heart (1 Sam 16:7), our intentions to seek Him are much more important than what religion we belong to.
Are you familiar with the sin of presumption? It's the idea that you know what it right yet choose not to do it, trusting that God will forgive you. If God lays out a path for us to follow, we should ALWAYS try to follow it, even though we know ahead of time that we will stumble and fall and need His forgiveness. Yes, God sees our inner desires and judges us to be Jews/Christians or not accordingly, and we all know ahead of time that we will need an amazingly abundant amount of forgiveness for the many, many times we will sin, but STILL we should make the attempt to obey God. If He said to be circumcised, and we know that, we should be circumcised. If He said to follow hundreds of laws governing every aspect of our lives, we should attempt to do so. Even though God's mercy surely extends to people who are earnestly seeking Him but have not yet found Him, denying them the opportunity to know Him and presume upon that mercy is never the right answer. He has made Himself known; we need to share that knowledge with everyone who is open to receiving it.