16 “When you fast, do not look sombre as the hypocrites do, for they disfigure their faces to show others they are fasting. Truly I tell you, they have received their reward in full.
17 But when you fast, put oil on your head and wash your face,
18 so that it will not be obvious to others that you are fasting, but only to your Father, who is unseen; and your Father, who sees what is done in secret, will reward you.
Can you imagine surviving 40 days without food or drink, couldn’t do it. Don’t think I would last 24 hours never mind 40 days.
However despite being tempted by the devil whilst in the wilderness Jesus’ faith was still strong enough to see off the devil and the 40 days of fasting.