You are correct...we are sowers...
As scripture states....some plant, others water
Yes and it is politics that began the decline of the church that Jesus started through Peter.
When people use the term politics you generally think of government. I may be misunderstanding what you are saying maam, if you mean church politics, then yes I agree to a great extent.
Jesus knew that God's Kingdom was no part of the world, not any government on earth, in fact he knew that satan was in charge of the earthly kingdoms, and that point was truly brought home to him when he personally was offered all the kingdoms of the world if he would simply do a simple act of worship to satan.
If you are meaning the latter that it was church politics, or disagreements with the ruling faction that is absolutely correct. It has been nearly 2k yrs since the birth of the Christian faith, and like the division of cells, 1 divided forming 2 then others divided and continuing on to our day it has resulted in thousands of sects claiming to be Christian.
(Acts 20:29, 30) . . .I know that after my going away oppressive wolves will enter in among you and will not treat the flock with tenderness, 30 and from among you yourselves men will rise and speak twisted things to draw away the disciples after themselves.
(1 Timothy 4:1) However, the inspired word clearly says that in later times some will fall away from the faith, paying attention to misleading inspired statements and teachings of demons,
(2 Timothy 4:3, 4) For there will be a period of time when they will not put up with the wholesome teaching, but according to their own desires, they will surround themselves with teachers to have their ears tickled. 4 They will turn away from listening to the truth and give attention to false stories.
(1 John 2:18, 19) Young children, it is the last hour, and just as you have heard that the antichrist is coming, even now many antichrists have appeared, from which fact we know that it is the last hour. 19 They went out from us, but they were not of our sort; for if they had been of our sort, they would have remained with us. But they went out so that it might be shown that not all are of our sort.