When to remove insignificant variables?

I'm working on logistic regression model. I checked the summary of the model which is built on 5 independent variables out which one is not significant with a P-value of 0.74.I wish to know that do we directly remove the variable or is there any other way to check for it's significance?

A senior of mine suggested to do logarithmic transformation of the insignificant variable & look for correlation then. Will that count towards checking it's significance.

model <- glm(Buy ~ a_score + b_score+ c_score+lb+p, data = history, family = binomial)

All variables come out to be significant with 2 or 3 stars apart from a_score which is shown insignificant.