Here "hold tightly" is a metaphor that refers to a person determining to do something and refusing to stop. The abstract nouns "confession" and "expectation" can be translated as verbs. AT: "Let us be determined to continue confessing the things that we confidently expect from God" (See: [[rc://en/ta/man/translate/figs-metaphor]] and [[rc://en/ta/man/translate/figs-abstractnouns]])
Being uncertain about something is spoken of as if he were wavering or leaning from side to side. AT: "without being unsure" or "without doubting" (See: [[rc://en/ta/man/translate/figs-metaphor]])
You can make explicit that the people met to worship. AT: "Let us not stop coming together to worship" (See: [[rc://en/ta/man/translate/figs-explicit]])
A future time is spoken of as if it were an object coming closer to the speaker. Here "the day" refers to when Jesus will return. AT: "as you know that Christ will return soon" (See: [[rc://en/ta/man/translate/figs-metaphor]] and [[rc://en/ta/man/translate/figs-metonymy]])