Jesus does not call us to follow Him because He wants or needs followers. In fact, He wants us to be saved and knows that only by hearing and heeding His saving voice can we be saved. Jesus is not interested in numbers or statistics. What He is going for is YOU and me. He saves us one soul at a time, not by mass conversion but by the Holy Spirit working through the Word spoken into the ear and then into the heart so that faith may sprout and grow. Jesus does not get anything out of this salvation business except YOU and me. And that is exactly how He wants it to be.
When Jesus invites us to take up our cross and follow Him, to deny ourselves and follow Him, to a cross-shaped life of suffering following Him, it is not because His cross is not enough or His suffering is not complete. It is because in order to follow Him we walk in His path, in but not of the world, against the enemies of sin, death, and the devil He faced. Indeed, by being close to Jesus we will not and cannot avoid the suffering, persecution, and threats He faced and He warned we, too, would face.
Sin has so corrupted our thinking and our desires that we presume we have something God wants or needs and therefore salvation is a sort of bargain or barter in which we exchange with God the things He desires for the things we need. We make God a beggar or at least a businessman who exchanges one thing of value for another. It is reasonable and logical to us but that does not make it true or accurate. We want God to be like us, to act like us, and to want the things we want, so that He is understandable and approachable. But God lives on holy ground, with glory we dare not see unless He makes it possible, and He acts in ways that contradict all reason and human expectation. Who would give up his only son to save strangers who were enemies and guilty, undeserving sinners? No one, of course, except God. He does not need us but we need Him. Salvation is no transaction but surrender -- surrender of our self-imagined value for the reality of what sin has made of us for the value God in the great surprise of His mercy has placed upon us. Not with silver or gold but with His holy and precious body in suffering and His blood shed. He does not need us but He wants us and though we do not want Him, we need Him most of all. Faith is the Holy Spirit teaching us to want what we need.