I believe implicitly that the child is not born mischievous in the bad sense of the term. If parents would behave themselves whilst the child is growing, before it is born and after, it is a well-known fact that the child would instinctively obey the law of truth and the law of love.
And believe me, from my experience of hundreds I was going to say thousands- of children. I know that they have perhaps a finer sense of honour than you or I have. The greatest lessons of life, if we would but stoop and humble ourselves, we would learn not from grown-up learned men, but from the so-called ignorant children. Jesus never uttered a loftier or a grander truth than when he said that wisdom cometh out of the mouth of babes. I believe it. I have noticed it in my experience that if we would approach babes in humility and innocence, we would learn wisdom from them. I have learned this one lesson- that what is impossible with man is child’s play with God and if we have faith in that Divinity which presides on the destiny of the meanest of His creation, I have no doubt that all things are possible and in that final hope, I believe and pass my time and endeavor to obey His will. If we are to reach real peace in this world and if we are to carry on a real war against war, we shall have to begin with children, and if they will grow up in their natural innocence, we won’t have to struggle, we won’t have to pass fruitless, idle resolutions, but we shall go from love to love and peace to peace, until at last all the corners of the world are covered with that peace and love for which, consciously or unconsciously, the whole world is hungering.

Which will of God is the author referring to in the line, I believe and pass my time and endeavor to obey His will?