Jesus himself, talking about his return, said that ‘concerning that day and hour no one knows, not even the angels of heaven, nor the Son, but the Father only’ (Mat. 24:36). We do not know when Jesus will return; in fact, when he does return, it will be very sudden (Mat. 24:42-51; Mat. 25:13; 1 Thess. 5:2-6; Rev. 16:15). Because of this, we need to be ready all the time:
Therefore you also must be ready, for the Son of Man is coming at an hour you do not expect. [Mat. 24:44]
Perhaps a strong indication that Jesus’ return could be near is the fact that the Jews are back as a nation in the land of Israel after having been exiled — the modern nation of Israel was declared in 1948. This is potentially a strong sign that Jesus could return soon because prophecies indicate that the Jews need to be in the land of Israel at the time when Jesus returns (e.g. Ezek. 38:8,14,16,18).