To the weak I became weak, to win the weak. I have become all things to all people so that by all possible means I might save some.
NIV
To the weak (wanting in discernment) I have become weak (wanting in discernment) that I might win the weak and overscrupulous. I have [in short] become all things to all men, that I might by all means (at all costs and in any and every way) save some [by winning them to faith in Jesus Christ].
AMP
To the weak became I as weak, that I might gain the weak: I am made all things to all men, that I might by all means save some.
KJV