The only reason why anyone believes in Election is because he finds it clearly taught in God's Word. No man, or number of men, ever originated this doctrine - AW Pink

"The only reason why anyone believes in Election is because he finds it clearly taught in God's Word. No man, or number of men, ever originated this doctrine. Like the teaching of Eternal Punishment, it conflicts with the dictates of the carnal mind and is repugnant to the sentiments of the unregenerate heart. And like the doctrine of the Holy Trinity and the miraculous birth of our Saviour, the truth of Election must be received with simple, unquestioning faith" 

AW Pink

(The Doctrines of Election and Justification pp. 3-4).

The nature of election is that God, by His divine will, selects some for salvation. While this may be hard to understand, it is the plain teaching of Scripture. The doctrine of election is both an exciting and intensely humbling reality.