There are a few passages in the bible such as Hebrews 10:23-25:
"Let us hold firmly the public declaration of our hope without wavering, for the one who promised is faithful. 24 And let us consider one another so as to incite to love and fine works, 25 not forsaking our meeting together, as some have the custom, but encouraging one another, and all the more so as you see the day drawing near."
So at our Christian meetings we can up-build and encourage one another. This can be anything from a quick complement, conversation, making plans for bible study, so on.
Another way of strengthening our faith is spreading our knowledge of the bibles message of hope publicly.