'Remain' in the Bible

Now, little children (believers, dear ones), remain in Him [with unwavering faith], so that when He appears [at His return], we may have [perfect] confidence and not be ashamed and shrink away from Him at His coming.

But whoever has the world’s goods (adequate resources), and sees his brother in need, but has no compassion for him, how does the love of God live in him?

By this we know [with confident assurance] that we abide in Him and He in us, because He has given to us His [Holy] Spirit.