Gregory the Great
Catena Aurea · Johannesevangelium 15
This is my commandment, That ye love one another, as I have loved you. Greater love hath no man than this, that a man lay down his life for his friends. Ye are my friends, if ye do whatsoever I command you. Henceforth I call you not servants; for the servant knoweth not what his Lord doeth: but I have called you friends; for all things that I have heard of my Father I have made known unto you. Ye have not chosen me, but I have chosen you, and ordained you, that ye should go and bring forth fruit, and that your fruit should remain: that whatsoever ye shall ask of the Father in my name, he may give it you.
(Hom. xxvii.) But whoso in time of tranquillity will not give up his time to God, how in persecution will he give up his soul? Let the virtue of love then, that it may be victorious in tribulation, be nourished in tranquillity by deeds of mercy.