10 types of people we will meet..

1. atheists (including most materialistic people)
2. agnostic (a skeptic of all levels)
3. ritualistic follower (blind followers)
4. impersonalist
5. other types of yogis
6. people who pray to Demigods
7. people from other religions (including who worship human beings)
8. people who pray for material benefits
9. caste Brahmins (for that matter any caste specific worship)
10. people who believe all pathways lead to the same goal
    

This constitutes 99% of the world population in the subject matter of God. Hence not surprised Krishna says

bahūnāḿ janmanām ante
jñānavān māḿ prapadyate
vāsudevaḥ sarvam iti
sa mahātmā su-durlabhaḥ
BG 7.19

After many births and deaths, he who is actually in knowledge surrenders unto Me, knowing Me to be the cause of all causes and all that is. Such a great soul is very rare.

Also, we have to be ready when we preach; we will face a person fitting in one of the above categories. Depending on the type of person we meet we have to engage them accordingly. So the only way to make them understand about Krishna is to show them love and compassion in a genuine and sincere manner. Be tolerant and patient with them…and the rest Krishna will take care.

Hare Krishna