Smith Wigglesworth is quoted as saying:
Smith largely believed his ministerial success was due to his speaking in tongues. He said:
“I want you to see that he that speaketh in an unknown tongue edifieth himself or builds himself up. We must be edified before we can edify the church. I cannot estimate what I, personally, owe to the Holy Ghost method of spiritual edification. I am here before you as one of the biggest conundrums in the world. There never was a weaker man on the platform. Language? None. Inability–full of it. All natural things in my life point exactly opposite to my being able to stand on the platform and preach the gospel. The secret is that the Holy Ghost came and brought this wonderful edification of the Spirit. I had been reading this Word continually as well as I could, but the Holy Ghost came and took hold of it, for the Holy Ghost is the breath of it, and He illuminated it to me.”
It is that simple!