“The Spirit itself  beareth witness with our spirit, that we are the children of God.” – Romans 8:16

“This verse therefore reminds us in a striking manner of the essential difference between the slavish spirit of Roman Catholicism and the “liberty of the Spirit” which is, I say, the hallmark of true Protestantism.” – D. Martyn Lloyd-Jones 

“The Roman Catholic teaching is opposed to the doctrine of  assurance of salvation. Their teaching is that a Christian can never be sure of his salvation.” – D. Martyn Lloyd-Jones