Can a new player ever beat a diamond?

My friend and I were both in a bit of a slump in our ranked games, so we decided to play each other. It was a pretty fun time!
He uses a mono-white angel deck that has a lot of life-gain mechanics. It's pretty strong, and he's beat me with it several times.
I'm using a mono-green deck focused on getting big creatures out and loading them up with +1/+1 counters. It's pretty fun, but sometimes feels outmatched.
Thanks for watching everyone! I appreciate your time and any feedback you want to give. Have a great day!
#gaming #magicthegathering #mtgarena #versus #magic