If there is a god then does god know the rising of atheists and the shrinking of Christians? Does god know why?

the problem is not anything to do with atheists, God, Jesus, the bible, or even Christianity and all to do with the intolerance, hatred, bigotry, homophobia and persecution posted by BAD Christians towards others!

The fact of the matter, God has predicted it in God Holy Word the Bible, there will be a falling away first. read 2 Thessalonians 2:1-4 Now We beseech you, brethren by the coming of our Lord Jesus Christ, and by our gathering together unto him, That ye be not soon shaken in mind, or be troubled, neither by spirit, nor by word, nor by letter as from us, as that the day of Christ is at hand. Let no man deceive you by any means: for that day shall not come, except there come a falling away first, and that man of sin be revealed, the son of perdition; Who opposeth and exalteth himself above all that is called God, or that is worshipped; so that God, shewing himself that he is God.

The current percentage is 7% non-theist and the rest some form of theist or undecided I couldn't care less about 7% it will be way after my lifetime that that percentage becomes anything that I need to be concerned against at the current time there is plenty of theists to beat the living hell I don't know those that are non-theists and that's really all I care about

Where?

Major reasons:

1. There's thousands of gods known to man, clearly man makes them up.

2. No almighty being, creator of the universe, would test, punish save and demand blind faith.

3. Jesus never came back.

4. Failure of prayer beyond any statistical measure of coincidence.

5. Bible stories are complete nonsense.

Be careful, because the church and the bank are also married.

Your "then" statement and question cannot be answered because your "if" statement is false.

Why do you assume that god cares about religions?

Why do you assume that the abrahamic/biblical concept of god is the correct one?

Yes. God knows all.

BTW - God shows no partiality towards Christians.