God is drawing all men. He wants all men to be saved. But because we have free will, not all will choose to believe.
'IF I BE
LIFTED UP' The action of this verb is
aorist/passive/subjunctive, which means that without having any reference to time
(aorist), Christ is to have this action acted upon Him
(passive) as to lifting or exalting Him not as a fact that will take place, but potentially or possibly
(subjunctive), which may or may not occur. In other words Jesus was saying that He has to be exalted by others, which may or may not occur at any time, but if He is lifted up from the earth then ...
'I WILL
DRAW ALL MEN UNTO ME' The action of this verb is
future/active/indicative, which means that at a later time
(future) when a certain action has taken place (lifted up) He will produce the action
(active) and draw or drag off all men unto Himself, which will occur as a fact
(indicative) in the future in response to being lifted up.
ALL MEN means individually or collectively. This would include ALL that His blood was shed for and had suffered death being judged for ALL sin. By virtue of the fact that He died for ALL sinners, then ALL those that are drawn by Him, as He is lifted up, will have the opportunity through grace to believe upon Him. To as many as receive Him, to them gave He the power to become the sons of God, even to them that believe on His name (Jn 1:12). This is why we must respond to the call of God and go out into ALL the world and preach the gospel to EVERY creature (Mk 16:15).